Tata cara perhitungan harga satuan pekerjaan pondasi untuk konstruksi bangunan gedung dan perumahan. Standart ini disusun oleh panitia teknik bahan konstruksi bangunan dan rekayasa sipil melalui gugus kerja struktur dan konstruksi bangunan pada subpanitia teknis bahan, sains, struktur dankonstruksi bangunan.
Tata cara penulisan disusun mengikuti pedoman SNI 08:2007 dan telah dibahas dalam rapat konsensus.
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Rabu, 03 November 2010
Senin, 20 September 2010
STRUT AND TIE MODEL FOR DEEP BEAM DESIGN
A lthough the Strut and Tie
Method (STM) has been used
for several years in Europe1,2 and
has been included in the Canadian
Standard for the Design of Concrete
Structures3 since 1984 and the
AASHTO LRFD Bridge Specifications4
since 1994, it is a new concept
for many structural engineers in the
U.S. Procedures and recommendations
for the use of STM to design
reinforced concrete members were
discussed in a State-of-the-Art
Report from Joint ACI-ASCE Committee
445, Shear and Torsion,5 but
specific code requirements were not
incorporated into the ACI Building
Code until the 2002 edition,6 as
Appendix A. To help U.S. engineers
improve their ability to use STM for
analysis and design of concrete
members, Joint ACI-ASCE Committee
445 and ACI Committee 318-E,
Shear and Torsion, recently completed
a publication that contains a variety
of STM examples.7 The STM model
used here for the analysis and
design of a deep beam is not unique.
It should be noted that the STM
procedure in Appendix A of the ACI
Building Code (referred to as the
Code) is a strength limit-state design
approach. Serviceability limit-states
(for example, deflections and
reinforcement distribution) defined
in the main body of the Code must
also be checked.
Download File
DESIGN of REINFORCED CONCRETE DEEP BEAMS Download File
Method (STM) has been used
for several years in Europe1,2 and
has been included in the Canadian
Standard for the Design of Concrete
Structures3 since 1984 and the
AASHTO LRFD Bridge Specifications4
since 1994, it is a new concept
for many structural engineers in the
U.S. Procedures and recommendations
for the use of STM to design
reinforced concrete members were
discussed in a State-of-the-Art
Report from Joint ACI-ASCE Committee
445, Shear and Torsion,5 but
specific code requirements were not
incorporated into the ACI Building
Code until the 2002 edition,6 as
Appendix A. To help U.S. engineers
improve their ability to use STM for
analysis and design of concrete
members, Joint ACI-ASCE Committee
445 and ACI Committee 318-E,
Shear and Torsion, recently completed
a publication that contains a variety
of STM examples.7 The STM model
used here for the analysis and
design of a deep beam is not unique.
It should be noted that the STM
procedure in Appendix A of the ACI
Building Code (referred to as the
Code) is a strength limit-state design
approach. Serviceability limit-states
(for example, deflections and
reinforcement distribution) defined
in the main body of the Code must
also be checked.
Download File
DESIGN of REINFORCED CONCRETE DEEP BEAMS Download File
Basic tools of Reinforced Concrete Beam Design
Basic tools of Reinforced Concrete Beam Design Download File
Diaphragm Effects in Retangular Reinforced Concrete Building
Diaphragm Effects in Retangular Reinforced Concrete Building Download File
A Nonlinear Analysis Method for Perfomance Based Seismic Design
A Nonlinear Analysis Method for Perfomance Based Seismic Design Download File
A Simple Seismic Desiogn Strategy Based on Displancement and Ductility Compatibility
Download File
A Simple Seismic Desiogn Strategy Based on Displancement and Ductility Compatibility
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Design Charts for Open - Channel Flow HDS 3 August 1961
Design of Highway Drainage Channels
The design of a highway drainage channel to carry a given discharge is accomplished in two
parts. The first part of the design involves the computation of a channel section which will carry
the design discharge on the available slope. This chapter briefly discusses the principles of flow
in open channels and the use of the Manning equation for computing the channel capacity.
The second part of the design is the determination of the degree of protection required to
prevent erosion in the drainage channel. This can be done by computing the velocity in the
channel at the design discharge, using the Manning equation, and comparing the calculated
velocity with that permissible for the type of channel lining used. (Permissible velocities are
shown in Table 2 and Table 3.) A change in the type of channel lining will require a change in
channel size unless both linings have the same roughness coefficient.
Types of Flow
Flow in open channels is classified as steady or unsteady. The flow is said to be steady when
the rate of discharge is not varying with time. In this chapter, the flow will be assumed to be
steady at the discharge rate for which the channel is to be designed. Steady flow is further
classified as uniform when the channel cross section, roughness, and slope are constant; and
as nonuniform or varied when the channel properties vary from section to section.
Depth of flow and the mean velocity will be constant for steady flow in a uniform channel.
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The design of a highway drainage channel to carry a given discharge is accomplished in two
parts. The first part of the design involves the computation of a channel section which will carry
the design discharge on the available slope. This chapter briefly discusses the principles of flow
in open channels and the use of the Manning equation for computing the channel capacity.
The second part of the design is the determination of the degree of protection required to
prevent erosion in the drainage channel. This can be done by computing the velocity in the
channel at the design discharge, using the Manning equation, and comparing the calculated
velocity with that permissible for the type of channel lining used. (Permissible velocities are
shown in Table 2 and Table 3.) A change in the type of channel lining will require a change in
channel size unless both linings have the same roughness coefficient.
Types of Flow
Flow in open channels is classified as steady or unsteady. The flow is said to be steady when
the rate of discharge is not varying with time. In this chapter, the flow will be assumed to be
steady at the discharge rate for which the channel is to be designed. Steady flow is further
classified as uniform when the channel cross section, roughness, and slope are constant; and
as nonuniform or varied when the channel properties vary from section to section.
Depth of flow and the mean velocity will be constant for steady flow in a uniform channel.
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HYDRAULICS IN CIVIL AND ENVIRONMENTAL ENGINEERNG
HYDRAULICS IN CIVIL AND ENVIRONMENTAL ENGINEERNG
This manual has been prepared for use in cojunction with the textbook
HYDRAULICS IN CIVIL AND ENVIRONMENTAL ENGINEERNG (4th editon).
The problems for solution in the book cover the material found in Chapters 1-11
The solutions manual is particularly inteded for use by course tutors.
It provides detailed method of solution for all of the problems in the 4th edition,
so that they can be integrated into the tutorial scheme for a hydraulics lecture programme.
Download File
This manual has been prepared for use in cojunction with the textbook
HYDRAULICS IN CIVIL AND ENVIRONMENTAL ENGINEERNG (4th editon).
The problems for solution in the book cover the material found in Chapters 1-11
The solutions manual is particularly inteded for use by course tutors.
It provides detailed method of solution for all of the problems in the 4th edition,
so that they can be integrated into the tutorial scheme for a hydraulics lecture programme.
Download File
RIVER ENGINEERING FOR HIGHWAY ENCROACHMENTS
The purpose of this chapter is to lay the groundwork for application of the concepts of
open-channel flow, fluvial geomorphology, sediment transport, and river mechanics to the
design, maintenance, and environmental problems associated with highway crossings and
encroachments.
This manual is a basic reference for related Federal Highway Administration (FHWA) hydraulic
publications and National Highway Institute (NHI) Hydraulics Courses. Some of these
publications are: "Hydraulics of Bridge Waterways" (Bradley 1978), "Design of Riprap
Revetment" (Brown and Clyde 1989), "Evaluating Scour at Bridges" (Richardson and Davis
2001), "Stream Stability at Highway Structures" (Lagasse et al. 2001), "Bridge Scour and
Stream Instability Countermeasures - Experience, Selection and Design Guidance" (Lagasse
et al. 2001). Related NHI courses include:
(1) River Engineering for Highway Encroachments,
(2) Stream Stability and Scour at Highway Bridges, and
(3) Finite Element Surface Water
Modeling System (FESWMS).
Basic definitions of terms and notations adopted for use in this document have been presented
in the preceding section (Glossary) for rapid reference. Additionally, these important terms and
variables are defined and explained as they are encountered.
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open-channel flow, fluvial geomorphology, sediment transport, and river mechanics to the
design, maintenance, and environmental problems associated with highway crossings and
encroachments.
This manual is a basic reference for related Federal Highway Administration (FHWA) hydraulic
publications and National Highway Institute (NHI) Hydraulics Courses. Some of these
publications are: "Hydraulics of Bridge Waterways" (Bradley 1978), "Design of Riprap
Revetment" (Brown and Clyde 1989), "Evaluating Scour at Bridges" (Richardson and Davis
2001), "Stream Stability at Highway Structures" (Lagasse et al. 2001), "Bridge Scour and
Stream Instability Countermeasures - Experience, Selection and Design Guidance" (Lagasse
et al. 2001). Related NHI courses include:
(1) River Engineering for Highway Encroachments,
(2) Stream Stability and Scour at Highway Bridges, and
(3) Finite Element Surface Water
Modeling System (FESWMS).
Basic definitions of terms and notations adopted for use in this document have been presented
in the preceding section (Glossary) for rapid reference. Additionally, these important terms and
variables are defined and explained as they are encountered.
Download File
Minggu, 05 September 2010
Bridge Scour and Stream Instability Countermeasures: Experience, Selection, and Design Guidance-Third Edition Volume 2
In this volume design guidelines are provided for a variety of stream instability and bridge
scour countermeasures. Most of these countermeasures have been applied successfully on
a state or regional basis, but, in several cases, only limited design references are available in
published handbooks, manuals, or reports. No attempt has been made to include in this
document design guidelines for all the countermeasures listed or referenced in Volume 1.
Countermeasure design guidelines formerly presented in HEC-20 (spurs, guide banks, drop
structures) and in HEC-18 (riprap at abutments and piers) are now consolidated in this
document. Since many bridge scour and stream instability countermeasures require riprap
revetment as an integral component of the countermeasure, riprap revetment design
guidance is summarized in Design Guideline 4. An appropriate granular or geotextile filter is
essential for any countermeasure requiring a protective armor layer (e.g., riprap, articulating
concrete blocks, etc.). Filter design guidance is provided in Design Guideline 16.
Design Guideline 8 – Articulating Concrete Block Systems, Design Guideline 9 –
Grout-Filled Mattresses, and Design Guideline 10 – Gabion Mattresses each contain
two countermeasure applications: (1) bankline revetment or bed armor, and (2) pier
scour protection. Consequently, these three design guidelines appear in Section 2,
but are referenced in Section 3 with a page citation to the pier protection application.
A number of highway agencies provided specifications, procedures, or design guidelines for
bridge scour and stream instability countermeasures that have been used successfully
locally, but for which only limited design guidance is available outside the agency. Several of
these are presented as design guidelines for the consideration of and possible adaptation to
the needs of other highway agencies (see for example, Design Guideline 6, Wire Enclosed
Riprap Mattress, and Design Guideline 13, Grout/Cement Filled Bags). These specifications,
procedures, or guidelines have not been evaluated, tested, or endorsed by the authors of
this document or by the FHWA. They are presented here in the interests of information
transfer on countermeasures that may have application in another state or region.
Since publication of the Second Edition of HEC-23 in 2001, both the Transportation
Research Board through the NCHRP Program and FHWA have sponsored a number of
research projects to improve the state of practice in bridge scour and stream instability
countermeasure technology and provide definitive guidance to bridge owners in
countermeasure design. Among the projects that represent advances in countermeasure
technology that have been incorporated into the Design Guidelines are:
• NCHRP Report 544 - Environmentally Sensitive Channel and Bank Protection Measures
• NCHRP Report 568 - Riprap Design Criteria, Specifications, and Quality Control
• NCHRP Report 587 - Countermeasures to Protect Bridge Abutments from Scour
• NCHRP Report 593 - Countermeasures to Protect Bridge Piers from Scour
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scour countermeasures. Most of these countermeasures have been applied successfully on
a state or regional basis, but, in several cases, only limited design references are available in
published handbooks, manuals, or reports. No attempt has been made to include in this
document design guidelines for all the countermeasures listed or referenced in Volume 1.
Countermeasure design guidelines formerly presented in HEC-20 (spurs, guide banks, drop
structures) and in HEC-18 (riprap at abutments and piers) are now consolidated in this
document. Since many bridge scour and stream instability countermeasures require riprap
revetment as an integral component of the countermeasure, riprap revetment design
guidance is summarized in Design Guideline 4. An appropriate granular or geotextile filter is
essential for any countermeasure requiring a protective armor layer (e.g., riprap, articulating
concrete blocks, etc.). Filter design guidance is provided in Design Guideline 16.
Design Guideline 8 – Articulating Concrete Block Systems, Design Guideline 9 –
Grout-Filled Mattresses, and Design Guideline 10 – Gabion Mattresses each contain
two countermeasure applications: (1) bankline revetment or bed armor, and (2) pier
scour protection. Consequently, these three design guidelines appear in Section 2,
but are referenced in Section 3 with a page citation to the pier protection application.
A number of highway agencies provided specifications, procedures, or design guidelines for
bridge scour and stream instability countermeasures that have been used successfully
locally, but for which only limited design guidance is available outside the agency. Several of
these are presented as design guidelines for the consideration of and possible adaptation to
the needs of other highway agencies (see for example, Design Guideline 6, Wire Enclosed
Riprap Mattress, and Design Guideline 13, Grout/Cement Filled Bags). These specifications,
procedures, or guidelines have not been evaluated, tested, or endorsed by the authors of
this document or by the FHWA. They are presented here in the interests of information
transfer on countermeasures that may have application in another state or region.
Since publication of the Second Edition of HEC-23 in 2001, both the Transportation
Research Board through the NCHRP Program and FHWA have sponsored a number of
research projects to improve the state of practice in bridge scour and stream instability
countermeasure technology and provide definitive guidance to bridge owners in
countermeasure design. Among the projects that represent advances in countermeasure
technology that have been incorporated into the Design Guidelines are:
• NCHRP Report 544 - Environmentally Sensitive Channel and Bank Protection Measures
• NCHRP Report 568 - Riprap Design Criteria, Specifications, and Quality Control
• NCHRP Report 587 - Countermeasures to Protect Bridge Abutments from Scour
• NCHRP Report 593 - Countermeasures to Protect Bridge Piers from Scour
Download File
Sabtu, 04 September 2010
Refined 3D finite element modeling of partially restrained connections including slip
The effect of partially-restrained (PR) connections on the behavior of steel frames
and their potential economical benefits is well recognized [18]. However, many structural
analysis and design approaches still consider connections as either fixed or
pinned. This assumption is mainly due to convenience and the lack of common
analysis and design approaches that address PR connections. Despite many full-scale
experimental studies that have been conducted to date, there is still a need for a
better understanding of the mechanisms that effect the non-linear behavior of PR
connections [8].
Non-linear moment rotation response of connections was recognized in the early
1930s. Standardized functions have been developed starting from basic linear and
bilinear approximations to more sophisticated models based on polynomials, cubic
B-splines and power functions fitted to available experimental data. Sherbourne and
Bahaari [13] have recently presented a review of these functions. Frye and Morris
[9] were among the first to incorporate these standardized moment–rotation functions
in steel plane frame analysis to investigate the effect of the connections on the
frame behavior.
Moment rotation functions can be useful for designers in practice. These usually
include small number of parameters taken into account from limited test data. The
lack of a large and parametrized experimental database does not allow for generating
standardized functions. Thus, there is a need to be able to analytically generate a
reliable moment–rotation response of PR connections that can be used in analysis
and design.
Non-linear finite elements are an attractive tool for modeling connections. Early
attempts to use finite elements for analysis of PR connections was by Krishnamurthy
[11]. As in many early studies using finite elements, many simplifications are made
due to the limitations of computational power. More recent studies using finite
elements in modeling connections have focused on end plate connections
[6,7,10,13,14]. In these studies 2D and 3D models are used with various simplifications
in the geometry of members, the bolts, and contact conditions. The effect
of friction on the response of end plate connections is usually neglected in these
models [7,10].
Azizinamini [3–5] preformed an extensive and detailed experimental study for top
and bottom seat angle connections with double web angles along with pull tests. In
addition, simplified 3D FE models for the pull tests are also studied. One quarter of
the top angle in the connection is modeled with 3D elements to simulate a pull test.
The force–displacement relation was converted to a moment–rotation relation in
order to examine the role of the top angle on the behavior of the connection and
approximate the overall response of the connection with a pull test. Different assumptions
and simplifications are made in order to avoid detailed modeling and reduce
the computational effort.
Yang et al. [19] consider a double web angle connection where the angles are
bolted to the column flanges and welded to the beam web. The bolts and angle are
modeled using 3D finite elements and wedge elements are used to model the weld
region. Contact is included between the bolt head and angle. However, the contact
between the bolt shank and hole is ignored.
In the studies on end plate connections and the double web angle connection, the
bolts are transferring the loads axially, thus eliminating the need for combined contact
and friction modeling between the bolts and members. These models are therefore
limited to these types of PR connections. The bolted connections tested by
Azizinamini et al. [4,5] are investigated in this study. These top–bottom bolted seat
angle connections transfer the forces by friction by clamping the parts together with
the bolts. Modeling such a mechanism requires the inclusion of contact and slip
between the connection members.
In this study, a refined 3D modeling of PR bolted connections are performed
recognizing contact and friction effects. The modeling approach is general and capable
of modeling various types of geometries of PR connections by using parametric
meshing techniques. Therefore the time of generating detailed 3D geometries is
almost eliminated. A calibration method for the pretension of the bolts is presented.
In this method, parametric solutions are first generated separately for a single bolt
clamping semi-infinite plates. These solutions are used to specify initial pretension
values for the bolts in the full connection. The correct pretension values are then
examined and corrected in the full connection model to achieve accurate final values.
It is shown in this study that the response of the bolted PR connections are sensitive
to the pretension of the bolts, thus correctly modeling the pretension and slip is
important.
Download File
and their potential economical benefits is well recognized [18]. However, many structural
analysis and design approaches still consider connections as either fixed or
pinned. This assumption is mainly due to convenience and the lack of common
analysis and design approaches that address PR connections. Despite many full-scale
experimental studies that have been conducted to date, there is still a need for a
better understanding of the mechanisms that effect the non-linear behavior of PR
connections [8].
Non-linear moment rotation response of connections was recognized in the early
1930s. Standardized functions have been developed starting from basic linear and
bilinear approximations to more sophisticated models based on polynomials, cubic
B-splines and power functions fitted to available experimental data. Sherbourne and
Bahaari [13] have recently presented a review of these functions. Frye and Morris
[9] were among the first to incorporate these standardized moment–rotation functions
in steel plane frame analysis to investigate the effect of the connections on the
frame behavior.
Moment rotation functions can be useful for designers in practice. These usually
include small number of parameters taken into account from limited test data. The
lack of a large and parametrized experimental database does not allow for generating
standardized functions. Thus, there is a need to be able to analytically generate a
reliable moment–rotation response of PR connections that can be used in analysis
and design.
Non-linear finite elements are an attractive tool for modeling connections. Early
attempts to use finite elements for analysis of PR connections was by Krishnamurthy
[11]. As in many early studies using finite elements, many simplifications are made
due to the limitations of computational power. More recent studies using finite
elements in modeling connections have focused on end plate connections
[6,7,10,13,14]. In these studies 2D and 3D models are used with various simplifications
in the geometry of members, the bolts, and contact conditions. The effect
of friction on the response of end plate connections is usually neglected in these
models [7,10].
Azizinamini [3–5] preformed an extensive and detailed experimental study for top
and bottom seat angle connections with double web angles along with pull tests. In
addition, simplified 3D FE models for the pull tests are also studied. One quarter of
the top angle in the connection is modeled with 3D elements to simulate a pull test.
The force–displacement relation was converted to a moment–rotation relation in
order to examine the role of the top angle on the behavior of the connection and
approximate the overall response of the connection with a pull test. Different assumptions
and simplifications are made in order to avoid detailed modeling and reduce
the computational effort.
Yang et al. [19] consider a double web angle connection where the angles are
bolted to the column flanges and welded to the beam web. The bolts and angle are
modeled using 3D finite elements and wedge elements are used to model the weld
region. Contact is included between the bolt head and angle. However, the contact
between the bolt shank and hole is ignored.
In the studies on end plate connections and the double web angle connection, the
bolts are transferring the loads axially, thus eliminating the need for combined contact
and friction modeling between the bolts and members. These models are therefore
limited to these types of PR connections. The bolted connections tested by
Azizinamini et al. [4,5] are investigated in this study. These top–bottom bolted seat
angle connections transfer the forces by friction by clamping the parts together with
the bolts. Modeling such a mechanism requires the inclusion of contact and slip
between the connection members.
In this study, a refined 3D modeling of PR bolted connections are performed
recognizing contact and friction effects. The modeling approach is general and capable
of modeling various types of geometries of PR connections by using parametric
meshing techniques. Therefore the time of generating detailed 3D geometries is
almost eliminated. A calibration method for the pretension of the bolts is presented.
In this method, parametric solutions are first generated separately for a single bolt
clamping semi-infinite plates. These solutions are used to specify initial pretension
values for the bolts in the full connection. The correct pretension values are then
examined and corrected in the full connection model to achieve accurate final values.
It is shown in this study that the response of the bolted PR connections are sensitive
to the pretension of the bolts, thus correctly modeling the pretension and slip is
important.
Download File
A simple shear wall model taking into account stiffness degradation
Complex destructive phenomena take place in
reinforced concrete structures during earthquake excitations.
These include concrete cracking, interaction
effects between steel and concrete, steel yielding and
concrete crushing in compression. The damage generated
can be translated into a damage variable which takes
the local destructive effects into account in a global manner.
As damage increases within the reinforced concrete
structure, the alteration of the mechanical characteristics
yields modal characteristics changes. In this way, Chen
et al. [1] investigated the structural damage by means of
the identification method of modal changes. At a critical
damage level, they indicated that a decrease of the fundamental
frequency up to 10% can be expected for steel
beams. For reinforced concrete structures, the fundamen-
tal frequency reduction, related to the structural damage
can be significantly larger. Pseudodynamic tests carried
out at the European Laboratory for Structural Assessment
(JRC-Ispra) in fact showed fundamental frequency
reductions of more than 60% (Pegon et al. [2]). Such
fundamental frequency decrease strongly influences the
dynamic response of the structure subjected to a seismic
excitation.
In this paper, a simplified model for a particular lowrise
heavily reinforced shear wall is proposed. Its original
formulation is based explicitly on changes in fundamental
frequency according to a pertinent damage variable.
First of all, a detailed finite element analysis is
carried out with constitutive local models taking into
account the main destructive phenomena involved during
seismic excitation. The relevance of the modelling
is evaluated by comparing numerical results with experimental
available data. The following stage is devoted
to the identification of the decrease of the fundamental
frequency. This is realised by applying the finite element
modelling of the wall to a variety of ideal excitations
composed of sinusoidal cycles. The numerical results
allow to identify in a robust manner the decrease of the
fundamental frequency as a function of damage. Then,
this function is introduced in a simple dynamic uniaxial
model, expressed in terms of displacements at the top of
the wall. In the final stage, the validity of the proposed
simplified model is assessed by comparing numerical
results with experimental results in a first time, and, in
a second time, with the results issued from fine finite
element analyses for different types of seismic excitations.
Download File
reinforced concrete structures during earthquake excitations.
These include concrete cracking, interaction
effects between steel and concrete, steel yielding and
concrete crushing in compression. The damage generated
can be translated into a damage variable which takes
the local destructive effects into account in a global manner.
As damage increases within the reinforced concrete
structure, the alteration of the mechanical characteristics
yields modal characteristics changes. In this way, Chen
et al. [1] investigated the structural damage by means of
the identification method of modal changes. At a critical
damage level, they indicated that a decrease of the fundamental
frequency up to 10% can be expected for steel
beams. For reinforced concrete structures, the fundamen-
tal frequency reduction, related to the structural damage
can be significantly larger. Pseudodynamic tests carried
out at the European Laboratory for Structural Assessment
(JRC-Ispra) in fact showed fundamental frequency
reductions of more than 60% (Pegon et al. [2]). Such
fundamental frequency decrease strongly influences the
dynamic response of the structure subjected to a seismic
excitation.
In this paper, a simplified model for a particular lowrise
heavily reinforced shear wall is proposed. Its original
formulation is based explicitly on changes in fundamental
frequency according to a pertinent damage variable.
First of all, a detailed finite element analysis is
carried out with constitutive local models taking into
account the main destructive phenomena involved during
seismic excitation. The relevance of the modelling
is evaluated by comparing numerical results with experimental
available data. The following stage is devoted
to the identification of the decrease of the fundamental
frequency. This is realised by applying the finite element
modelling of the wall to a variety of ideal excitations
composed of sinusoidal cycles. The numerical results
allow to identify in a robust manner the decrease of the
fundamental frequency as a function of damage. Then,
this function is introduced in a simple dynamic uniaxial
model, expressed in terms of displacements at the top of
the wall. In the final stage, the validity of the proposed
simplified model is assessed by comparing numerical
results with experimental results in a first time, and, in
a second time, with the results issued from fine finite
element analyses for different types of seismic excitations.
Download File
Performance of reinforced concrete buildings during, Turkey earthquake, and seismic design and construction practise in Turkey
On August 17, 1999, a Mw 7.4 earthquake occurred
on the 1500-km-long North Anatolian fault in northwestern
Turkey. The epicenter of the earthquake was near
Izmit, 90 km east of Istanbul (Fig. 1). Following the
earthquake, the Pacific Earthquake Engineering
Research Center dispatched a reconnaissance team to the
epicentral region to learn first hand about the performance
of the civil infrastructure. The geographic region
that was impacted by the earthquake was somewhat narrow
banded and centered around the fault, and stretched
from Istanbul in the west to Go¨lyaka and Du¨zce in the
east. Damage to building construction was severe and
widespread (Sezen et al. [1], Aschheim [2], Scawthorn
[3]). Estimates for economic losses were around 20
billion US dollars. The official death toll was over
17,200, with some 44,000 people injured and thousands
left homeless. Some 77,300 homes and businesses were
destroyed, and 244,500 were damaged. The majority of
deaths and injuries were in the cities of Kocaeli, Sakarya,
and Yalova.
This paper describes briefly the state-of-practice for
building seismic design and construction in Turkey, and
compares the US and Turkish codes. The performance
of the reinforced concrete frame and wall buildings and
their components during the 1999 Kocaeli earthquake is
presented, and evaluated considering the seismic design
and construction practice in the epicentral region.
Download File
on the 1500-km-long North Anatolian fault in northwestern
Turkey. The epicenter of the earthquake was near
Izmit, 90 km east of Istanbul (Fig. 1). Following the
earthquake, the Pacific Earthquake Engineering
Research Center dispatched a reconnaissance team to the
epicentral region to learn first hand about the performance
of the civil infrastructure. The geographic region
that was impacted by the earthquake was somewhat narrow
banded and centered around the fault, and stretched
from Istanbul in the west to Go¨lyaka and Du¨zce in the
east. Damage to building construction was severe and
widespread (Sezen et al. [1], Aschheim [2], Scawthorn
[3]). Estimates for economic losses were around 20
billion US dollars. The official death toll was over
17,200, with some 44,000 people injured and thousands
left homeless. Some 77,300 homes and businesses were
destroyed, and 244,500 were damaged. The majority of
deaths and injuries were in the cities of Kocaeli, Sakarya,
and Yalova.
This paper describes briefly the state-of-practice for
building seismic design and construction in Turkey, and
compares the US and Turkish codes. The performance
of the reinforced concrete frame and wall buildings and
their components during the 1999 Kocaeli earthquake is
presented, and evaluated considering the seismic design
and construction practice in the epicentral region.
Download File
Seismic behaviour of self centring braced frame buildings with reusable hysteretic damping brace
Structural systems designed with conventional seismic design approach dissipate seismic energy by
incurring ductile inelastic response in selected regions. Such a seismic design strategy may not be
appealing from a life cycle cost perspective, especially for high seismic regions, where costly repairs
are often required after moderate earthquakes. After the 1994 Northridge earthquakes, growing
interests are given to a more logical seismic design approach, which involves energy dissipation
through supplemental damping system or fuse-type energy-dissipating devices. In such systems, the
main structural system is intended to have little or no damage while supplemental damping devices
are designed directly for energy dissipation and can be replaced if damaged during earthquakes.
Examples of such energy dissipation devices include friction damper, buckling-restrained brace
and many other types of passive or active structural control devices [1].
Buckling-restrained braces (BRB), which are capable of yielding in both tension and compression,
have been developed to overcome the buckling problem of conventional braces in concentrically
braced frames [2, 3]. BRB frame has been used extensively for seismic applications in Japan
after the 1995 Kobe earthquake and is also gaining popularity in the United States after the 1994
Northridge earthquake. BRB frames are desirable for seismic design and rehabilitation for their
superior ductile performance. Non-linear dynamic analyses by Sabelli et al. [2] have shown that
the behaviour of BRB frames is comparable and often better than that associated with conventional
concentrically braced frames and moment frames. However, several potential problems such as
tendency of BRBs to yield under frequent earthquakes have been identified for BRB frame by
a few researchers [2, 4]. Costly repair after moderately strong earthquakes might be necessary
due to these problems. For example, large residual displacements may exist in a BRB frame
after moderate earthquakes, necessitating closure of the building while costly repairs are being
carried out.
Recently, an alternative seismic resisting system with self-centring hysteretic behaviours has
received considerable interests (e.g. [5–7]). A flag-shaped hysteresis loop is typical of such selfcentring
systems with energy dissipation capability. Self-centring systems have the ability to control
damage and to reduce (or even eliminate) residual structural deformation. This is important since
residual structural deformation is emphasized as a fundamental complementary parameter in the
evaluation of structural (and non-structural) damage in the performance-based seismic design and
assessment approach [8].
Although several self-centring structural systems using post-tensioned high strength steel bars
or tendons have been proposed [5, 6, 9], special metals such as superelastic shape memory alloys
(SMA) possess a self-centring hysteretic behaviour which can be utilized to construct self-centring
braced frame systems. However, without pre-tensioning, superelastic SMA would most likely
remain linearly elastic and thus no energy dissipation would occur under frequent earthquakes.
SMA-based energy dissipation devices have recently attracted a great attention from civil engineering
researchers for seismic response control applications (e.g. [10–17]). Hodgson and Krumme [10]
proposed a SMA damping device with a centre-tapped configuration, in which the superelastic
wires are loaded to the middle of its superelastic strain limit when the device is constructed. This
centre-tapped configuration allows the device to dissipate energy in both push and pull directions.
Dolce et al. [13] tested Nitinol-based devices with full re-centring and good energy dissipation
capabilities. The kernel component of such a device consists of two groups of Nitinol wire loops—a
re-centring group of Nitinol wires with pre-strain and an energy-dissipating group of pre-tensioned
superelastic Nitinol wires, which are mounted on two concentric tubes. Their full-scale brace,
which was designed for a maximum force of 200 kN and has a double flag-shaped hysteretic
loop, can be used as a bracing element in framed structures. The ability of these SMA braces to
control the seismic response of RC framed structures was assessed through shaking table tests of a
1
3.3 -scale, 3-storey, two-bay RC plane frame, which was designed for low seismicity and low ductility
[14]. Their experimental results have shown that the SMA braces can provide performances
at least comparable to those provided by steel braces, while having an additional self-centring
feature.
This paper presents a special hysteretic damping device termed reusable hysteretic damping
brace (RHDB) with inherent self-centring behaviour and enhanced energy dissipation capacity.
A new type of self-centring braced frame system can be established by combining the concepts
of braced frames and self-centring system using RHDB. A seismic performance study of steel
concentrically braced frames with RHDBs, which is based on non-linear time history analysis of
RHDB frames, is the focus of this paper. The non-linear dynamic analysis involves a 3-storey and
6-storey concentrically braced frames subjected to design basis earthquake and frequent earthquake
ground motions for California.
Download File
incurring ductile inelastic response in selected regions. Such a seismic design strategy may not be
appealing from a life cycle cost perspective, especially for high seismic regions, where costly repairs
are often required after moderate earthquakes. After the 1994 Northridge earthquakes, growing
interests are given to a more logical seismic design approach, which involves energy dissipation
through supplemental damping system or fuse-type energy-dissipating devices. In such systems, the
main structural system is intended to have little or no damage while supplemental damping devices
are designed directly for energy dissipation and can be replaced if damaged during earthquakes.
Examples of such energy dissipation devices include friction damper, buckling-restrained brace
and many other types of passive or active structural control devices [1].
Buckling-restrained braces (BRB), which are capable of yielding in both tension and compression,
have been developed to overcome the buckling problem of conventional braces in concentrically
braced frames [2, 3]. BRB frame has been used extensively for seismic applications in Japan
after the 1995 Kobe earthquake and is also gaining popularity in the United States after the 1994
Northridge earthquake. BRB frames are desirable for seismic design and rehabilitation for their
superior ductile performance. Non-linear dynamic analyses by Sabelli et al. [2] have shown that
the behaviour of BRB frames is comparable and often better than that associated with conventional
concentrically braced frames and moment frames. However, several potential problems such as
tendency of BRBs to yield under frequent earthquakes have been identified for BRB frame by
a few researchers [2, 4]. Costly repair after moderately strong earthquakes might be necessary
due to these problems. For example, large residual displacements may exist in a BRB frame
after moderate earthquakes, necessitating closure of the building while costly repairs are being
carried out.
Recently, an alternative seismic resisting system with self-centring hysteretic behaviours has
received considerable interests (e.g. [5–7]). A flag-shaped hysteresis loop is typical of such selfcentring
systems with energy dissipation capability. Self-centring systems have the ability to control
damage and to reduce (or even eliminate) residual structural deformation. This is important since
residual structural deformation is emphasized as a fundamental complementary parameter in the
evaluation of structural (and non-structural) damage in the performance-based seismic design and
assessment approach [8].
Although several self-centring structural systems using post-tensioned high strength steel bars
or tendons have been proposed [5, 6, 9], special metals such as superelastic shape memory alloys
(SMA) possess a self-centring hysteretic behaviour which can be utilized to construct self-centring
braced frame systems. However, without pre-tensioning, superelastic SMA would most likely
remain linearly elastic and thus no energy dissipation would occur under frequent earthquakes.
SMA-based energy dissipation devices have recently attracted a great attention from civil engineering
researchers for seismic response control applications (e.g. [10–17]). Hodgson and Krumme [10]
proposed a SMA damping device with a centre-tapped configuration, in which the superelastic
wires are loaded to the middle of its superelastic strain limit when the device is constructed. This
centre-tapped configuration allows the device to dissipate energy in both push and pull directions.
Dolce et al. [13] tested Nitinol-based devices with full re-centring and good energy dissipation
capabilities. The kernel component of such a device consists of two groups of Nitinol wire loops—a
re-centring group of Nitinol wires with pre-strain and an energy-dissipating group of pre-tensioned
superelastic Nitinol wires, which are mounted on two concentric tubes. Their full-scale brace,
which was designed for a maximum force of 200 kN and has a double flag-shaped hysteretic
loop, can be used as a bracing element in framed structures. The ability of these SMA braces to
control the seismic response of RC framed structures was assessed through shaking table tests of a
1
3.3 -scale, 3-storey, two-bay RC plane frame, which was designed for low seismicity and low ductility
[14]. Their experimental results have shown that the SMA braces can provide performances
at least comparable to those provided by steel braces, while having an additional self-centring
feature.
This paper presents a special hysteretic damping device termed reusable hysteretic damping
brace (RHDB) with inherent self-centring behaviour and enhanced energy dissipation capacity.
A new type of self-centring braced frame system can be established by combining the concepts
of braced frames and self-centring system using RHDB. A seismic performance study of steel
concentrically braced frames with RHDBs, which is based on non-linear time history analysis of
RHDB frames, is the focus of this paper. The non-linear dynamic analysis involves a 3-storey and
6-storey concentrically braced frames subjected to design basis earthquake and frequent earthquake
ground motions for California.
Download File
Pumice concrete for structural wall panels
Structural lightweight aggregate concrete (LWC) has
been used in many civil engineering applications as a very
convenient alternative to conventional concrete. As a matter
of fact its lighter weight permits a saving in dead load
with a reduction in the costs of both superstructures and
foundations. In addition, the better thermal insulation, the
greater fire resistance and the substantially equivalent
sound-proofing properties (in spite of its minor mass compared
to normal weight concrete (NWC) — see e.g. [1])
make it preferable with respect to NWC itself for nonstructural
uses.
In the last five decades the use of LWC has been
extended to structural elements, thanks to the improvement
in performances obtainable (in terms of stiffness, strength
and ductility) by means of appropriate ingredient mix proportions
[2] and appropriate design of the reinforcement.
Naturally, the use of lightweight concrete has been confined
to large structures (where the beneficial influences of
the reduced weight are greater), and, more in particular, to
structures where a high dead load to live load ratio occurs.
Further, the reduced weight may make LWC preferable for
structures in seismic zones, because of the reduced
dynamic actions, and for precast structures, because it
makes it easier to move the elements to be connected.
More recently, lightweight concrete was also applied in
marine structures (offshore structures and ships), and later
for long span bridges, buildings and grandstands [1]. Referring
to buildings, LWC can be used in structural frames,
but it proves to be more suitable for wall system structures,
where the local ductility demand (in seismic zones) and
the required strength of the materials are reduced and the
dead load to live load ratio is very high.
LWC is manufactured by using different kinds of lightweight
aggregates, available in nature or artificially produced,
so that the properties of LWC depend on the properties
of the particular lightweight aggregate being used.
Natural lightweight aggregate sources can be found in
regions characterized by volcanic activity, where porous
rocks (known as pumices), are available. Artificial lightweight
aggregates (like the expanded clay obtained by
thermal treatment of argillaceous materials) are produced
in many countries, the raw materials being very common.
They may exhibit higher resistance than natural
lightweight aggregates, but this favourable result implies
a greater production cost.
Considering the availability of pumice in the world
and its usability as a natural aggregate for concrete, a
research program has been carried out in order to verify
the mechanical properties of the pumice concrete in
relation to the mechanical standards requested by
present-day codes for structural applications, and in
order to observe its behaviour when used for structural
elements. The main results at the actual stage of this
research are presented through the paper. Specifically,
the results of the tests on lightweight pumice stone concrete
(LWPSC) wall panels subjected to vertical and lateral
loads are shown and compared to those obtained
from similar NWC and lightweight expanded clay concrete
(LWECC) wall panels.
Download File
been used in many civil engineering applications as a very
convenient alternative to conventional concrete. As a matter
of fact its lighter weight permits a saving in dead load
with a reduction in the costs of both superstructures and
foundations. In addition, the better thermal insulation, the
greater fire resistance and the substantially equivalent
sound-proofing properties (in spite of its minor mass compared
to normal weight concrete (NWC) — see e.g. [1])
make it preferable with respect to NWC itself for nonstructural
uses.
In the last five decades the use of LWC has been
extended to structural elements, thanks to the improvement
in performances obtainable (in terms of stiffness, strength
and ductility) by means of appropriate ingredient mix proportions
[2] and appropriate design of the reinforcement.
Naturally, the use of lightweight concrete has been confined
to large structures (where the beneficial influences of
the reduced weight are greater), and, more in particular, to
structures where a high dead load to live load ratio occurs.
Further, the reduced weight may make LWC preferable for
structures in seismic zones, because of the reduced
dynamic actions, and for precast structures, because it
makes it easier to move the elements to be connected.
More recently, lightweight concrete was also applied in
marine structures (offshore structures and ships), and later
for long span bridges, buildings and grandstands [1]. Referring
to buildings, LWC can be used in structural frames,
but it proves to be more suitable for wall system structures,
where the local ductility demand (in seismic zones) and
the required strength of the materials are reduced and the
dead load to live load ratio is very high.
LWC is manufactured by using different kinds of lightweight
aggregates, available in nature or artificially produced,
so that the properties of LWC depend on the properties
of the particular lightweight aggregate being used.
Natural lightweight aggregate sources can be found in
regions characterized by volcanic activity, where porous
rocks (known as pumices), are available. Artificial lightweight
aggregates (like the expanded clay obtained by
thermal treatment of argillaceous materials) are produced
in many countries, the raw materials being very common.
They may exhibit higher resistance than natural
lightweight aggregates, but this favourable result implies
a greater production cost.
Considering the availability of pumice in the world
and its usability as a natural aggregate for concrete, a
research program has been carried out in order to verify
the mechanical properties of the pumice concrete in
relation to the mechanical standards requested by
present-day codes for structural applications, and in
order to observe its behaviour when used for structural
elements. The main results at the actual stage of this
research are presented through the paper. Specifically,
the results of the tests on lightweight pumice stone concrete
(LWPSC) wall panels subjected to vertical and lateral
loads are shown and compared to those obtained
from similar NWC and lightweight expanded clay concrete
(LWECC) wall panels.
Download File
Prediction of elastic displacement response spectra in Europe and the Middle East
Empirical equations are presented for the prediction of displacement response ordinates for damping ratios
of 2, 5, 10, 20 and 30% of critical and for response periods up to 4 s, using 532 accelerograms from the
strong-motion databank from Europe and the Middle East. The records were all re-processed and only
employed for regressions at periods within the usable range, defined as a fraction of the filter cut-off
and depending on the instrument type (digital or analogue), earthquake magnitude and site class. The
equations can be applied to predict the geometric mean displacement and pseudo-acceleration spectra
for earthquakes with moment magnitudes (M) between 5 and 7.6, and for distances up to 100 km. The
equations also include style-of-faulting and site class as explanatory variables. The predictions obtained
from these new equations suggest that earlier European equations for spectral displacements underestimate
the ordinates at longer periods as a result of severe filtering and the use of the spectral ordinates at periods
too close to the filter cut-off. The results also confirm that the period defining the start of the constant
displacement plateau in the Eurocode 8 (EC8) spectrum is excessively short at 2 s. The results not only
show that the scaling factor defined in EC8 for estimating the spectral ordinates at damping ratios different
from 5% of critical are a good general approximation, but also that this scaling varies with magnitude and
distance (reflecting the influence of duration) and also displays a mild dependence on response period.
Copyright q 2007 John Wiley & Sons, Ltd.
Download File
of 2, 5, 10, 20 and 30% of critical and for response periods up to 4 s, using 532 accelerograms from the
strong-motion databank from Europe and the Middle East. The records were all re-processed and only
employed for regressions at periods within the usable range, defined as a fraction of the filter cut-off
and depending on the instrument type (digital or analogue), earthquake magnitude and site class. The
equations can be applied to predict the geometric mean displacement and pseudo-acceleration spectra
for earthquakes with moment magnitudes (M) between 5 and 7.6, and for distances up to 100 km. The
equations also include style-of-faulting and site class as explanatory variables. The predictions obtained
from these new equations suggest that earlier European equations for spectral displacements underestimate
the ordinates at longer periods as a result of severe filtering and the use of the spectral ordinates at periods
too close to the filter cut-off. The results also confirm that the period defining the start of the constant
displacement plateau in the Eurocode 8 (EC8) spectrum is excessively short at 2 s. The results not only
show that the scaling factor defined in EC8 for estimating the spectral ordinates at damping ratios different
from 5% of critical are a good general approximation, but also that this scaling varies with magnitude and
distance (reflecting the influence of duration) and also displays a mild dependence on response period.
Copyright q 2007 John Wiley & Sons, Ltd.
Download File
Simplified Estimation of Economic Seismic Risk for Buildings
Seismic risk enters into several important real-estate decision-making processes:
purchase of investment property, performance-based design of new structures, seismic
rehabilitation of existing buildings, and decisions regarding the purchase of earthquake
insurance, for example. In such situations, it matters who the decision makers are, how
they make decisions, what aspects of seismic risk most concern them, how long their
planning horizon is, and other parameters. We focus on one of the more common seismic
risk decision situations: the purchase of existing commercial property by real-estate
investors in seismic regions. (The most common situation is probably purchasing a home
in seismically active regions.)
Economic seismic risk to these properties is assessed every time the property
changes hands, on the order of every five to ten years. By contrast, a building is designed
and built only once. Thus the most common opportunity for market forces to
bring about seismic-risk mitigation for commercial properties is at times of sale. Anecdotal
evidence suggests that these are mostly missed opportunities: risk is typically not
mitigated, even in more vulnerable buildings.
This can be partly explained by considering the context in which seismic assessments
are performed. During virtually every sale of an existing commercial building, the
buyer assesses the building’s investment value using a financial analysis that considers
revenues and expenses, rent roll, market leasing, physical condition, and other property
information. The investor makes his or her bidding decision based on projected income
and expenses, using one or more of the economic performance metrics of net present
value, net operating income, cashflow, internal rate of return, and capitalization rate.
The input to this financial analysis is typically provided by a real-estate broker representing
the seller, whose figures the investor checks and modifies during a duediligence
study. Many of the inputs are known values—number, duration, and income
from current leases, for instance—but many are uncertain. Vacancy rates, market rents,
and other important parameters fluctuate significantly and unpredictably, leading to substantial
uncertainty in the future economic performance of a property. In the face of
these uncertainties, the bidder usually estimates investment value using best-estimate inputs
and then again with deterministic sensitivity studies to probe conditions that would
lead to poor performance (higher future vacancy rates, for example). The future cost to
repair earthquake damage is not one of the parameters the bidder uses in the financial
analysis. This is important: seismic risk is not a market quantity.
Download File
purchase of investment property, performance-based design of new structures, seismic
rehabilitation of existing buildings, and decisions regarding the purchase of earthquake
insurance, for example. In such situations, it matters who the decision makers are, how
they make decisions, what aspects of seismic risk most concern them, how long their
planning horizon is, and other parameters. We focus on one of the more common seismic
risk decision situations: the purchase of existing commercial property by real-estate
investors in seismic regions. (The most common situation is probably purchasing a home
in seismically active regions.)
Economic seismic risk to these properties is assessed every time the property
changes hands, on the order of every five to ten years. By contrast, a building is designed
and built only once. Thus the most common opportunity for market forces to
bring about seismic-risk mitigation for commercial properties is at times of sale. Anecdotal
evidence suggests that these are mostly missed opportunities: risk is typically not
mitigated, even in more vulnerable buildings.
This can be partly explained by considering the context in which seismic assessments
are performed. During virtually every sale of an existing commercial building, the
buyer assesses the building’s investment value using a financial analysis that considers
revenues and expenses, rent roll, market leasing, physical condition, and other property
information. The investor makes his or her bidding decision based on projected income
and expenses, using one or more of the economic performance metrics of net present
value, net operating income, cashflow, internal rate of return, and capitalization rate.
The input to this financial analysis is typically provided by a real-estate broker representing
the seller, whose figures the investor checks and modifies during a duediligence
study. Many of the inputs are known values—number, duration, and income
from current leases, for instance—but many are uncertain. Vacancy rates, market rents,
and other important parameters fluctuate significantly and unpredictably, leading to substantial
uncertainty in the future economic performance of a property. In the face of
these uncertainties, the bidder usually estimates investment value using best-estimate inputs
and then again with deterministic sensitivity studies to probe conditions that would
lead to poor performance (higher future vacancy rates, for example). The future cost to
repair earthquake damage is not one of the parameters the bidder uses in the financial
analysis. This is important: seismic risk is not a market quantity.
Download File
On the characteristics of ground motion rotational components using Chiba dense array data
Rotational motions (torsional and rocking) induced by seismic waves have been essentially
ignored for a long time, first because rotational effects were thought to be small for man-made
structures [1], and second because sensitive measuring devices were not available until quite recently.
The benefits of the determination of rotational motion in seismology and engineering are
still under investigation (e.g. [2, 3]). In seismology, rotational motions can provide accurate data
for arrival times of SH waves and, in the near-source distance range, rotational motions might
provide more detailed information on the rupture processes of earthquakes [3]. Rotational motions
could also be used to better estimate the static displacement from seismic recordings, identifying
translational signals caused by rotation [2].
In engineering, dynamic response estimation of structures subjected to earthquake-induced base
excitations is often simplified by ignoring the rotational components. This has been a widely
accepted practice in engineering community, mainly caused by the lack of recorded strong motion
accelerograms for these motions. Many structural failures and the damage caused by earthquakes
can be linked to differential and rotational ground motions. Torsional responses of tall buildings in
Los Angeles, during the San Fernando earthquake in 1971, could be ascribed to torsional excitation,
while rotational and longitudinal differential motions may have caused the collapse of bridges
during San Fernando (1971), Miyagi-ken-Oki (1978) [4] and Northridge (1994) [5] earthquakes.
For the first time, Newmark [6] established a simple relationship between translational and torsional
components of the ground motion. He presented a deterministic procedure for estimating the
increase in displacement of symmetric-plan buildings caused by rotational ground motions at the
base due to horizontal propagation of plane waves with a constant velocity and further explored
in the other studies [7, 8]. Several studies have shown the importance of torsional components
in seismic analysis and design of structures [6, 9–13]. The seismic design codes also prescribe
‘Accidental Eccentricity’ in design force calculations to account for the unknown torsional inputs
and unpredictable eccentricities [14, 15]. Since then, many researchers have studied the dynamic
and accidental eccentricities of structures [12, 13, 16, 17]. The significance of rocking excitations
for continuous [18] and for base-isolated structures [19] is emphasized. Furthermore, the effects of
rocking motions on dynamic response of multistorey building have been analytically investigated
and the results revealed that stiff structures, such as nuclear power plants, having short vibration
periods, might be influenced more by this component in typical earthquake excitations [20].
Although some theoretical studies [20–22] have been carried out to estimate effects of rocking
components on response of structures, no provisions are made in design codes to account for the
effect of ground rocking motion.
Download File
ignored for a long time, first because rotational effects were thought to be small for man-made
structures [1], and second because sensitive measuring devices were not available until quite recently.
The benefits of the determination of rotational motion in seismology and engineering are
still under investigation (e.g. [2, 3]). In seismology, rotational motions can provide accurate data
for arrival times of SH waves and, in the near-source distance range, rotational motions might
provide more detailed information on the rupture processes of earthquakes [3]. Rotational motions
could also be used to better estimate the static displacement from seismic recordings, identifying
translational signals caused by rotation [2].
In engineering, dynamic response estimation of structures subjected to earthquake-induced base
excitations is often simplified by ignoring the rotational components. This has been a widely
accepted practice in engineering community, mainly caused by the lack of recorded strong motion
accelerograms for these motions. Many structural failures and the damage caused by earthquakes
can be linked to differential and rotational ground motions. Torsional responses of tall buildings in
Los Angeles, during the San Fernando earthquake in 1971, could be ascribed to torsional excitation,
while rotational and longitudinal differential motions may have caused the collapse of bridges
during San Fernando (1971), Miyagi-ken-Oki (1978) [4] and Northridge (1994) [5] earthquakes.
For the first time, Newmark [6] established a simple relationship between translational and torsional
components of the ground motion. He presented a deterministic procedure for estimating the
increase in displacement of symmetric-plan buildings caused by rotational ground motions at the
base due to horizontal propagation of plane waves with a constant velocity and further explored
in the other studies [7, 8]. Several studies have shown the importance of torsional components
in seismic analysis and design of structures [6, 9–13]. The seismic design codes also prescribe
‘Accidental Eccentricity’ in design force calculations to account for the unknown torsional inputs
and unpredictable eccentricities [14, 15]. Since then, many researchers have studied the dynamic
and accidental eccentricities of structures [12, 13, 16, 17]. The significance of rocking excitations
for continuous [18] and for base-isolated structures [19] is emphasized. Furthermore, the effects of
rocking motions on dynamic response of multistorey building have been analytically investigated
and the results revealed that stiff structures, such as nuclear power plants, having short vibration
periods, might be influenced more by this component in typical earthquake excitations [20].
Although some theoretical studies [20–22] have been carried out to estimate effects of rocking
components on response of structures, no provisions are made in design codes to account for the
effect of ground rocking motion.
Download File
A constitutive model of concrete confined by steel reinforcements and steel jackets
Many strong earthquakes, such as the 1990 Luzon earthquake
(Philippines), the 1994 Northridge earthquake (USA),
the 1995 Kobe earthquake (Japan), and the 1999 Ji-Ji earthquake
(Taiwan), have occurred in regions of high seismicity
in the last decade. These earthquakes resulted in sgnificant
loss of life and property and caused infrastructure damage.
The columns are the most important structural members in a
structure, and the strength and ductility of columns significantly
influence the seismic capacity of a structure. Therefore,
the seismic retrofit of a column has become a very
important issue in countries subject to earthquake activity.
In the 1990s, the steel jacketing technique was developed
and experimentally verified to be effective in enhancing the
seismic capacity of columns. Therefore, the steel jacketing
technique has been widely applied in practical construction,
particularly in Japan, Taiwan, and the state of California in
the United States.
The steel jacketing technique was originally developed for
circular-sectioned bridge columns. Two semicircular steel
plates larger than the diameter of the column are formed in
the factory. The vertical seams between both half steel shells
are welded in situ to become a continuous steel tube with a
small annular gap between the bridge column and the steel
plate. The gap is filled with pure cement or epoxy matrix to
transfer the stress in the bridge column to the steel plates
(Priestley et al. 1996). Therefore, concrete confined by a
steel jacket can be seen as that confined by continuous lateral
steel reinforcement. Steel jacketing has proven to be effective
because none of the bridges retrofitted with a steel
jacket suffered damage during the 1994 Northridge earthquake
(CALTRANS 1994). In Taiwan, the steel jacketing
technique has also become a very popular seismic retrofit
technique after the 1999 Ji-Ji earthquake.
The steel jacket mounted around the column can increase
the compressive strength, shear strength, and ductility of the
column. By doing so, the constitutive behavior of the concrete
is changed due to the increase in the confinement stress
of the concrete (Moehle 1992; Priestley and Seible 1991;
Priestley et al. 1996). Therefore, it is necessary to develop a
suitable constitutive model for concrete confined by a steel
jacket in the structural analysis and also the retrofit design.
In this paper, a constitutive model of concrete confined by
both steel reinforcement and a steel jacket in the use of
retrofitting and strengthening reinforced concrete structures
is proposed, and test results are also recorded from 60 concrete
cylinders, 30 cm in diameter and 60 cm in length, confined
by steel jackets of different thicknesses and different
types of lateral steel reinforcement. The stress–strain curves
of the test results are compared with that of the proposed constitutive
model to show that the proposed model is effective.
Download File
(Philippines), the 1994 Northridge earthquake (USA),
the 1995 Kobe earthquake (Japan), and the 1999 Ji-Ji earthquake
(Taiwan), have occurred in regions of high seismicity
in the last decade. These earthquakes resulted in sgnificant
loss of life and property and caused infrastructure damage.
The columns are the most important structural members in a
structure, and the strength and ductility of columns significantly
influence the seismic capacity of a structure. Therefore,
the seismic retrofit of a column has become a very
important issue in countries subject to earthquake activity.
In the 1990s, the steel jacketing technique was developed
and experimentally verified to be effective in enhancing the
seismic capacity of columns. Therefore, the steel jacketing
technique has been widely applied in practical construction,
particularly in Japan, Taiwan, and the state of California in
the United States.
The steel jacketing technique was originally developed for
circular-sectioned bridge columns. Two semicircular steel
plates larger than the diameter of the column are formed in
the factory. The vertical seams between both half steel shells
are welded in situ to become a continuous steel tube with a
small annular gap between the bridge column and the steel
plate. The gap is filled with pure cement or epoxy matrix to
transfer the stress in the bridge column to the steel plates
(Priestley et al. 1996). Therefore, concrete confined by a
steel jacket can be seen as that confined by continuous lateral
steel reinforcement. Steel jacketing has proven to be effective
because none of the bridges retrofitted with a steel
jacket suffered damage during the 1994 Northridge earthquake
(CALTRANS 1994). In Taiwan, the steel jacketing
technique has also become a very popular seismic retrofit
technique after the 1999 Ji-Ji earthquake.
The steel jacket mounted around the column can increase
the compressive strength, shear strength, and ductility of the
column. By doing so, the constitutive behavior of the concrete
is changed due to the increase in the confinement stress
of the concrete (Moehle 1992; Priestley and Seible 1991;
Priestley et al. 1996). Therefore, it is necessary to develop a
suitable constitutive model for concrete confined by a steel
jacket in the structural analysis and also the retrofit design.
In this paper, a constitutive model of concrete confined by
both steel reinforcement and a steel jacket in the use of
retrofitting and strengthening reinforced concrete structures
is proposed, and test results are also recorded from 60 concrete
cylinders, 30 cm in diameter and 60 cm in length, confined
by steel jackets of different thicknesses and different
types of lateral steel reinforcement. The stress–strain curves
of the test results are compared with that of the proposed constitutive
model to show that the proposed model is effective.
Download File
Ductility and linear analysis with moment redistribution in reinforced high strength concrete beams
The evaluation of the ductility of reinforced concrete beams is very important, since it is essential to avoid a
fragile collapse of the structure by ensuring adequate deformation at the ultimate limit state. One of the procedures
used to quantify ductility is based on deformations, namely, the plastic rotation capacity. Knowledge of the plastic rotation
capacity of certain regions of the structure is important for a plastic analysis or a linear analysis with moment redistribution.
An experimental program is described in this article. It is composed of 10 tests designed to study the moment
redistribution and ductility of continuous high-strength concrete beams. Particular care was given to analysing how the
tensile reinforcement ratio and the transverse reinforcement ratio influence the plastic rotation capacity of the beams. A
comparative study was carried out on several codes related to the moment redistribution permitted and the experimental
findings. It was found that some of the recommendations are unsafe. It was also found that high-strength concrete
beams, when properly designed, have enough deformation capacity to be used in plastic analysis.
Download File
fragile collapse of the structure by ensuring adequate deformation at the ultimate limit state. One of the procedures
used to quantify ductility is based on deformations, namely, the plastic rotation capacity. Knowledge of the plastic rotation
capacity of certain regions of the structure is important for a plastic analysis or a linear analysis with moment redistribution.
An experimental program is described in this article. It is composed of 10 tests designed to study the moment
redistribution and ductility of continuous high-strength concrete beams. Particular care was given to analysing how the
tensile reinforcement ratio and the transverse reinforcement ratio influence the plastic rotation capacity of the beams. A
comparative study was carried out on several codes related to the moment redistribution permitted and the experimental
findings. It was found that some of the recommendations are unsafe. It was also found that high-strength concrete
beams, when properly designed, have enough deformation capacity to be used in plastic analysis.
Download File
Failure tests on full scale models of grout laminated wood decks
A grout laminated wood deck (GLWD) comprises wood
laminates, or logs trimmed to obtain two vertical faces, held
together by internal grout cylinders, also referred to as shear
keys, which are prestressed with rods of steel or glass fibre
reinforced polymers (GFRP). There are two methods of constructing
GLWD. In one scheme of construction, the deck is
compressed laterally by tendons in regularly spaced transverse
holes within the deck. After stressing the deck, the
holes are filled with a grout. The prestressing force is removed
from the rods after the grout has set, thus putting the
grout cylinders in compression. For ease of reference, the
deck resulting from this method of construction is referred
to as the GLWD with grout cylinders in compression or
GLWD-C.
In the other method of construction, the deck is compressed
by an external prestressing system and the transverse
holes in the deck, containing the rods, are filled with a grout.
After the grout has set, the external prestressing system is
removed, inducing a tensile force in the grout cylinders,
most of which develop small transverse cracks along their
length. The deck obtained by this form of construction is referred
to as the GLWD with grout cylinders in tension or
GLWD-T.
Full-scale models of both forms of construction of GLWD
were constructed at Dalhousie University. The GLWD-C
employing steel rods was built about 3 years ago, and the
GLWD-T with GFRP rods about 2 years ago. A set of initial
tests conducted on the two models have confirmed that the
grout cylinders, whether cracked or not, are effective in the
lateral transfer of concentrated loads. Unlike stress laminated
wood decks, GLWDs are not affected by prestress
losses.
The two models of GLWDs were recently moved to The
University of Manitoba in Winnipeg, where each was tested
to failure under a central patch load. It was confirmed that
the decks can be assembled and stored for prolonged periods
of time without adversely affecting their performance, thus
making them an excellent choice for emergency use. The ultimate
load tests are described herein and the pre-failure test
results compared with those from the earlier tests.
Download File
laminates, or logs trimmed to obtain two vertical faces, held
together by internal grout cylinders, also referred to as shear
keys, which are prestressed with rods of steel or glass fibre
reinforced polymers (GFRP). There are two methods of constructing
GLWD. In one scheme of construction, the deck is
compressed laterally by tendons in regularly spaced transverse
holes within the deck. After stressing the deck, the
holes are filled with a grout. The prestressing force is removed
from the rods after the grout has set, thus putting the
grout cylinders in compression. For ease of reference, the
deck resulting from this method of construction is referred
to as the GLWD with grout cylinders in compression or
GLWD-C.
In the other method of construction, the deck is compressed
by an external prestressing system and the transverse
holes in the deck, containing the rods, are filled with a grout.
After the grout has set, the external prestressing system is
removed, inducing a tensile force in the grout cylinders,
most of which develop small transverse cracks along their
length. The deck obtained by this form of construction is referred
to as the GLWD with grout cylinders in tension or
GLWD-T.
Full-scale models of both forms of construction of GLWD
were constructed at Dalhousie University. The GLWD-C
employing steel rods was built about 3 years ago, and the
GLWD-T with GFRP rods about 2 years ago. A set of initial
tests conducted on the two models have confirmed that the
grout cylinders, whether cracked or not, are effective in the
lateral transfer of concentrated loads. Unlike stress laminated
wood decks, GLWDs are not affected by prestress
losses.
The two models of GLWDs were recently moved to The
University of Manitoba in Winnipeg, where each was tested
to failure under a central patch load. It was confirmed that
the decks can be assembled and stored for prolonged periods
of time without adversely affecting their performance, thus
making them an excellent choice for emergency use. The ultimate
load tests are described herein and the pre-failure test
results compared with those from the earlier tests.
Download File
An evaluation of pile cap design methods in accordance with the Canadian design standard
There are a number of design methods that have been described for the design of pile caps, but there has
been no consensus on which method provides the best approach for the working designer. This paper describes a study
conducted to establish the performance of several pile cap design methods, particularly with respect to the Canadian
standard, CSA A23.3-94. Previous research was examined to determine the basis of the design methods and the state
of current research. The design methods identified were then applied to pile caps for which test data were available.
The theoretical loads obtained using the various design methods were compared with the experimental loads. The results
of this study indicate that two design models of the five examined are the most suitable. This study also indicates
that the provisions of the Canadian design standard are adequate. A possible refinement of the strut-and-tie model incorporating
a geometric limit is also outlined.
Key words: building codes, footings, pile caps, reinforced concrete, structural design.
Résumé : Plusieurs méthodes de conception ont été décrites pour la conception des têtes de pieu, mais un consensus
n’a pas été atteint quant à savoir quelle méthode fournit la meilleure approche pour le concepteur. Cet article décrit
une étude effectuée pour déterminer le rendement de plusieurs méthodes de conception de semelles sur pieu, en particulier
par rapport au norme canadienne, CSA A23.3-94. Les recherches antérieures ont été examinées afin de déterminer
la base des méthodes de conception et l’état de la recherche actuelle. Les méthodes de conception identifiées ont
été appliquées aux semelles sur pieu pour lesquelles les données de tests étaient disponibles. Les charges théoriques
obtenues en utilisant les diverses méthodes de conception ont été comparées aux charges expérimentales. Les résultats
de cette étude indiquent que deux modèles de conception sur les cinq examinés étaient mieux adaptés. Cette étude indique
également que les dispositions de la norme canadienne de conception sont adéquates. Un raffinement possible du
modèle à treillis incorporant une limite géométrique est également souligné.
Download File
been no consensus on which method provides the best approach for the working designer. This paper describes a study
conducted to establish the performance of several pile cap design methods, particularly with respect to the Canadian
standard, CSA A23.3-94. Previous research was examined to determine the basis of the design methods and the state
of current research. The design methods identified were then applied to pile caps for which test data were available.
The theoretical loads obtained using the various design methods were compared with the experimental loads. The results
of this study indicate that two design models of the five examined are the most suitable. This study also indicates
that the provisions of the Canadian design standard are adequate. A possible refinement of the strut-and-tie model incorporating
a geometric limit is also outlined.
Key words: building codes, footings, pile caps, reinforced concrete, structural design.
Résumé : Plusieurs méthodes de conception ont été décrites pour la conception des têtes de pieu, mais un consensus
n’a pas été atteint quant à savoir quelle méthode fournit la meilleure approche pour le concepteur. Cet article décrit
une étude effectuée pour déterminer le rendement de plusieurs méthodes de conception de semelles sur pieu, en particulier
par rapport au norme canadienne, CSA A23.3-94. Les recherches antérieures ont été examinées afin de déterminer
la base des méthodes de conception et l’état de la recherche actuelle. Les méthodes de conception identifiées ont
été appliquées aux semelles sur pieu pour lesquelles les données de tests étaient disponibles. Les charges théoriques
obtenues en utilisant les diverses méthodes de conception ont été comparées aux charges expérimentales. Les résultats
de cette étude indiquent que deux modèles de conception sur les cinq examinés étaient mieux adaptés. Cette étude indique
également que les dispositions de la norme canadienne de conception sont adéquates. Un raffinement possible du
modèle à treillis incorporant une limite géométrique est également souligné.
Download File
Earthquake response of tall reinforced concrete chimneys
Codes of practice around the world provide conservative
guidelines for the aseismic design of tall reinforced
concrete chimneys in the belief that such structures
would behave in a brittle manner when subject to severe
earthquake excitation. This has resulted in reinforced
concrete chimneys being prohibitively expensive in
regions of high seismicity. It has recently been established
from an experimental program that reinforced
concrete chimneys respond in a moderately ductile manner
under severe reverse cycle loading through yielding
of the reinforcement in tension provided that the sections
possess a reasonable curvature capacity [1].
The results from the experimental program have been
used to develop a non linear dynamic procedure for evaluating
the inelastic response of tall reinforced concrete
chimney structures described in this paper. The procedure,
which incorporates a cantilever model with discrete
plastic hinges is used to study the response of ten
chimneys, ranging in height from 115 m to 301 m, to
severe earthquake excitation. In particular, the response
behaviour and the failure modes of these chimneys associated
with an ensemble of earthquake ground motions
is described.
Based on the non linear dynamic study, a series of
code design recommendations have been prepared which
encourage the development of ductile behaviour to dissipate
the seismic energy and prevent the formation of
brittle failure modes. These recommendations have been
incorporated into the 2001 CICIND code [2] for the
design of reinforced concrete chimneys and result in
cheaper chimneys which perform better under earthquake
excitation (CICIND is a French acronym for International
Committee on Industrial chimneys). The justification
for the selection of a structural response factor
of R=2 which reduces the seismic design forces and satisfies
both the serviceability and structural stability limit
states is presented using a deterministic approach.
Finally, a comparison of the cost and performance of a
245 m tall chimney designed to the proposed seismic
code provisions is made with the 1998 ACI 307, 1998
CICIND, 1996 EC8-3 and 1997 UBC codes of practice
[2–5].
Download File
guidelines for the aseismic design of tall reinforced
concrete chimneys in the belief that such structures
would behave in a brittle manner when subject to severe
earthquake excitation. This has resulted in reinforced
concrete chimneys being prohibitively expensive in
regions of high seismicity. It has recently been established
from an experimental program that reinforced
concrete chimneys respond in a moderately ductile manner
under severe reverse cycle loading through yielding
of the reinforcement in tension provided that the sections
possess a reasonable curvature capacity [1].
The results from the experimental program have been
used to develop a non linear dynamic procedure for evaluating
the inelastic response of tall reinforced concrete
chimney structures described in this paper. The procedure,
which incorporates a cantilever model with discrete
plastic hinges is used to study the response of ten
chimneys, ranging in height from 115 m to 301 m, to
severe earthquake excitation. In particular, the response
behaviour and the failure modes of these chimneys associated
with an ensemble of earthquake ground motions
is described.
Based on the non linear dynamic study, a series of
code design recommendations have been prepared which
encourage the development of ductile behaviour to dissipate
the seismic energy and prevent the formation of
brittle failure modes. These recommendations have been
incorporated into the 2001 CICIND code [2] for the
design of reinforced concrete chimneys and result in
cheaper chimneys which perform better under earthquake
excitation (CICIND is a French acronym for International
Committee on Industrial chimneys). The justification
for the selection of a structural response factor
of R=2 which reduces the seismic design forces and satisfies
both the serviceability and structural stability limit
states is presented using a deterministic approach.
Finally, a comparison of the cost and performance of a
245 m tall chimney designed to the proposed seismic
code provisions is made with the 1998 ACI 307, 1998
CICIND, 1996 EC8-3 and 1997 UBC codes of practice
[2–5].
Download File
Beam element verification for 3D elastic steel frame analysis
In the past decade, there has been more widespread
use of 3D frame analysis programs in civil engineering
design offices to determine the buckling loads and the
member forces of steel framed structures. In most cases,
the use of 3D analysis has been necessitated by the
topology of the designed structure that does not permit
the use of 2D analysis, such as in the case of a sports
stadium. More recently, however, 3D frame analyses
have also been carried out on multi-storey multi-bay
rectangular frames such as high-rise storage rack frames.
The fact that this type of steel structure is generally
composed of open sections rather than tubular sections,
the latter normally used in space roof trusses and offshore
structures, has important implications for the
frame stability that are not generally well understood by
practising engineers. In design practice, either linear
buckling analysis or second-order elastic analysis is
performed to assess the frame stability.
The elastic buckling behaviour and the second-order
effects due to geometric nonlinearity of steel plane
frames are well understood and well documented in the
literature [1–4]. Commercial frame analysis programs
that can handle most or all of these two stability aspects
of planar (2D) steel structures have also been available
for many years. For the purpose of verifying a 2D beam
element or a 2D frame analysis program, there are many
well established and well defined benchmark examples
[5–7]. However, neither situation is true for 3D beam
elements or 3D frame analysis programs. Although 3D
linear elastic analysis is a fairly straightforward extension
of 2D analysis, at the member level there may be 3D
couplings between axial, flexural and torsional deformation
modes that control the buckling behaviour of
open sections. The comment of Springfield [8] that few
commercial frame analysis/design programs could deal
with out-of-plane buckling of beams or beam-columns
by other than empirical means is still largely true today,
except for the more expensive general-purpose finite
element analysis packages such as ADINA [9] and
ABAQUS [10].
Download File
use of 3D frame analysis programs in civil engineering
design offices to determine the buckling loads and the
member forces of steel framed structures. In most cases,
the use of 3D analysis has been necessitated by the
topology of the designed structure that does not permit
the use of 2D analysis, such as in the case of a sports
stadium. More recently, however, 3D frame analyses
have also been carried out on multi-storey multi-bay
rectangular frames such as high-rise storage rack frames.
The fact that this type of steel structure is generally
composed of open sections rather than tubular sections,
the latter normally used in space roof trusses and offshore
structures, has important implications for the
frame stability that are not generally well understood by
practising engineers. In design practice, either linear
buckling analysis or second-order elastic analysis is
performed to assess the frame stability.
The elastic buckling behaviour and the second-order
effects due to geometric nonlinearity of steel plane
frames are well understood and well documented in the
literature [1–4]. Commercial frame analysis programs
that can handle most or all of these two stability aspects
of planar (2D) steel structures have also been available
for many years. For the purpose of verifying a 2D beam
element or a 2D frame analysis program, there are many
well established and well defined benchmark examples
[5–7]. However, neither situation is true for 3D beam
elements or 3D frame analysis programs. Although 3D
linear elastic analysis is a fairly straightforward extension
of 2D analysis, at the member level there may be 3D
couplings between axial, flexural and torsional deformation
modes that control the buckling behaviour of
open sections. The comment of Springfield [8] that few
commercial frame analysis/design programs could deal
with out-of-plane buckling of beams or beam-columns
by other than empirical means is still largely true today,
except for the more expensive general-purpose finite
element analysis packages such as ADINA [9] and
ABAQUS [10].
Download File
A comparison of single-run pushover analysis techniques for seismic assessment of bridges
The term ‘pushover analysis’ describes a modern variation of the classical ‘collapse analysis’
method, as fittingly described by Kunnath [1]. It refers to an analysis procedure whereby an
incremental-iterative solution of the static equilibrium equations has been carried out to obtain
the response of a structure subjected to monotonically increasing lateral load patterns. Whilst the
application of pushover methods in the assessment of building frames has been extensively verified
in the recent past, nonlinear static analysis of bridge structures has been the subject of only limited
scrutiny [2]. Since bridges are markedly different structural typologies with respect to buildings,
observations and conclusions drawn from studies on the latter cannot really be extrapolated to the
case of the former, as shown by Fischinger et al. [3], who highlighted the doubtful validity of
systematic application of standard pushover procedures to bridge structures.
Recent years have also witnessed the development and introduction of an alternative type of
nonlinear static analysis [4–10], which involve running multiple pushover analyses separately, each
of which corresponding to a given modal distribution, and then estimating the structural response
by combining the action effects derived from each of the modal responses (i.e. each displacement–
force pair derived from such procedures does not actually correspond to an equilibrated structural
stress state). As highlighted by some of their respective authors, the main advantage of this
category of static analysis procedures is that they may be applied using standard readily available
commercial software packages, since they make use of conventional analysis types. The associated
drawback, however, is that the methods are inevitably more complex than running a single pushover
analysis, as noted by Maison [11], for which reason they do not constitute the scope of the current
work, where focus is instead placed on single-run pushover analysis procedures, the simplicity
of which renders them an even more appealing alternative, or complement, to nonlinear dynamic
analysis [12].
In this work an analytical parametric study is thus conducted applying different single-run
pushover procedures, either adaptive or conventional, on a number of regular and irregular continuous
deck bridges subjected to an ensemble of ground motions. The effectiveness of each
methodology in reproducing both global behaviour and local phenomena is assessed by comparing
static analysis results with the outcomes of nonlinear time-history runs. Adaptive pushovers are
run in both their force-based [13–17] and displacement-based [18, 19] versions. With respect to
the latter, it is noted that, contrary to what happens in a non-adaptive pushover, where the application
of a constant displacement profile would force a predetermined and possibly inappropriate
response mode that could conceal important structural characteristics and concentrated inelastic
mechanisms at a given location, within an adaptive framework a displacement-based pushover
is entirely feasible, since the loading vector is updated at each step of the analysis according to
the current dynamic characteristics of the structure. The interested reader is referred to some of
the aforementioned publications for details on the underlying formulations of adaptive pushover
algorithms.
It is observed that whilst for regular bridge configurations some conventional single-run pushover
methods may manage to provide levels of accuracy that are similar to those yielded by their more
evolved adaptive counterparts, when irregular bridges are considered the advantages of using the
latter become evident. In particular, the displacement-based adaptive pushover (DAP) algorithm is
shown to lead to improved predictions, which match more closely results from nonlinear dynamic
analysis.
Download File
method, as fittingly described by Kunnath [1]. It refers to an analysis procedure whereby an
incremental-iterative solution of the static equilibrium equations has been carried out to obtain
the response of a structure subjected to monotonically increasing lateral load patterns. Whilst the
application of pushover methods in the assessment of building frames has been extensively verified
in the recent past, nonlinear static analysis of bridge structures has been the subject of only limited
scrutiny [2]. Since bridges are markedly different structural typologies with respect to buildings,
observations and conclusions drawn from studies on the latter cannot really be extrapolated to the
case of the former, as shown by Fischinger et al. [3], who highlighted the doubtful validity of
systematic application of standard pushover procedures to bridge structures.
Recent years have also witnessed the development and introduction of an alternative type of
nonlinear static analysis [4–10], which involve running multiple pushover analyses separately, each
of which corresponding to a given modal distribution, and then estimating the structural response
by combining the action effects derived from each of the modal responses (i.e. each displacement–
force pair derived from such procedures does not actually correspond to an equilibrated structural
stress state). As highlighted by some of their respective authors, the main advantage of this
category of static analysis procedures is that they may be applied using standard readily available
commercial software packages, since they make use of conventional analysis types. The associated
drawback, however, is that the methods are inevitably more complex than running a single pushover
analysis, as noted by Maison [11], for which reason they do not constitute the scope of the current
work, where focus is instead placed on single-run pushover analysis procedures, the simplicity
of which renders them an even more appealing alternative, or complement, to nonlinear dynamic
analysis [12].
In this work an analytical parametric study is thus conducted applying different single-run
pushover procedures, either adaptive or conventional, on a number of regular and irregular continuous
deck bridges subjected to an ensemble of ground motions. The effectiveness of each
methodology in reproducing both global behaviour and local phenomena is assessed by comparing
static analysis results with the outcomes of nonlinear time-history runs. Adaptive pushovers are
run in both their force-based [13–17] and displacement-based [18, 19] versions. With respect to
the latter, it is noted that, contrary to what happens in a non-adaptive pushover, where the application
of a constant displacement profile would force a predetermined and possibly inappropriate
response mode that could conceal important structural characteristics and concentrated inelastic
mechanisms at a given location, within an adaptive framework a displacement-based pushover
is entirely feasible, since the loading vector is updated at each step of the analysis according to
the current dynamic characteristics of the structure. The interested reader is referred to some of
the aforementioned publications for details on the underlying formulations of adaptive pushover
algorithms.
It is observed that whilst for regular bridge configurations some conventional single-run pushover
methods may manage to provide levels of accuracy that are similar to those yielded by their more
evolved adaptive counterparts, when irregular bridges are considered the advantages of using the
latter become evident. In particular, the displacement-based adaptive pushover (DAP) algorithm is
shown to lead to improved predictions, which match more closely results from nonlinear dynamic
analysis.
Download File
PERENCANAAN STRUKTUR GEDUNG INSTALASI RAWAT INAP RSI SURAKARTA
Rumah Sakit Islam Surakarta adalah salah satu Rumah Sakit Islam
swasta yang berada dibawah naungan Yayasan Rumah Sakit Islam
Surakarta (YARSIS). RSI Surakarta beralamat di Jl. Ahmad Yani, Pabelan
Surakarta. RSI Surakarta memiliki berbagai fasilitas pelayanan yang
memadai baik pelayanan umum maupun khusus. Saat ini terdapat 5
gedung utama yang telah digunakan, 3 diantaranya adalah gedung yang
digunakan untuk instalasi rawat inap. Instalasi rawat inap tersebut terdiri
dari rawat inap untuk kelas Very Important Person (VIP), kelas I dan
keluarga miskin.
Rumah Sakit Islam Surakarta dalam perkembangannya masih
memerlukan ruangan untuk instalasi rawat inap khususnya kelas VIP
sehingga diperlukan penambahan jumlah instalasi rawat inap, maka dari
itu dilaksanakanlah pembangunan gedung rawat inap RSI Surakarta.
Dalam perencanaannya gedung ini dibuat 6 tingkat. Lantai 1 direncanakan
untuk ruang administrasi dan manajemen, lantai 2 untuk ruang rawat inap
kelas VIP, lantai 3,4,5 untuk ruang rawat inap kelas 1 dan lantai 6 untuk
ruang mesin.
Pembangunan instalasi rawat inap yang baru diharapkan mampu
meningkatkan pelayanan rumah sakit kepada pasiennya dan menjadikan
Rumah Sakit Islam Surakarta sebagai salah satu Rumah Sakit Islam yang
bonafid serta mengutamakan pelayanan. .Hal itulah yang melatar belakangi
dibangunnya gedung rawat inap ini.
Download File
swasta yang berada dibawah naungan Yayasan Rumah Sakit Islam
Surakarta (YARSIS). RSI Surakarta beralamat di Jl. Ahmad Yani, Pabelan
Surakarta. RSI Surakarta memiliki berbagai fasilitas pelayanan yang
memadai baik pelayanan umum maupun khusus. Saat ini terdapat 5
gedung utama yang telah digunakan, 3 diantaranya adalah gedung yang
digunakan untuk instalasi rawat inap. Instalasi rawat inap tersebut terdiri
dari rawat inap untuk kelas Very Important Person (VIP), kelas I dan
keluarga miskin.
Rumah Sakit Islam Surakarta dalam perkembangannya masih
memerlukan ruangan untuk instalasi rawat inap khususnya kelas VIP
sehingga diperlukan penambahan jumlah instalasi rawat inap, maka dari
itu dilaksanakanlah pembangunan gedung rawat inap RSI Surakarta.
Dalam perencanaannya gedung ini dibuat 6 tingkat. Lantai 1 direncanakan
untuk ruang administrasi dan manajemen, lantai 2 untuk ruang rawat inap
kelas VIP, lantai 3,4,5 untuk ruang rawat inap kelas 1 dan lantai 6 untuk
ruang mesin.
Pembangunan instalasi rawat inap yang baru diharapkan mampu
meningkatkan pelayanan rumah sakit kepada pasiennya dan menjadikan
Rumah Sakit Islam Surakarta sebagai salah satu Rumah Sakit Islam yang
bonafid serta mengutamakan pelayanan. .Hal itulah yang melatar belakangi
dibangunnya gedung rawat inap ini.
Download File
Penyambungan tiang pancang beton pracetak untuk fondasi jembatan
Pedoman tentang Penyambungan tiang pancang beton pracetak untuk fondasi jembatan adalah revisi dari SNI 03-3448-1994, Tata cara penyambungan tiang pancang beton pracetak penampang persegi dengan sistem monolit bahan epoxy, yang dilengkapi dengan tata cara penyambungan tiang pancang beton pracetak dengan las dengan beberapa perubahan yang diuraikan pada deviasi teknis.
Pedoman ini disusun oleh Panitia Teknis Bahan Konstruksi Bangunan dan Rekayasa Sipil melalui Gugus Kerja Jembatan dan Bangunan Pelengkap Jalan pada Subpanitia Teknis Rekayasa Jalan dan Jembatan.
Tata cara penulisan disusun mengikuti Pedoman Standardisasi Nasional (PSN) Nomor 8 Tahun 2007 dan dibahas dalam forum konsensus tanggal 19 Desember 2007 di Bandung, yang melibatkan para narasumber, pakar dan lembaga terkait.
Download File
Pedoman ini disusun oleh Panitia Teknis Bahan Konstruksi Bangunan dan Rekayasa Sipil melalui Gugus Kerja Jembatan dan Bangunan Pelengkap Jalan pada Subpanitia Teknis Rekayasa Jalan dan Jembatan.
Tata cara penulisan disusun mengikuti Pedoman Standardisasi Nasional (PSN) Nomor 8 Tahun 2007 dan dibahas dalam forum konsensus tanggal 19 Desember 2007 di Bandung, yang melibatkan para narasumber, pakar dan lembaga terkait.
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Behaviour of Precast Concrete Beam for Earthquake Resistance and Fast Build House using Infill Frame System
Wilayah Indonesia mempunyai aktivitas
gempa yang cukup tinggi (puslitbang). Dampak yang
terjadi akibat gempa bumi tersebut adalah jatuhnya
korban jiwa dan keruntuhan sebagian besar bangunan,
khususnya rumah tinggal. Sebagian besar rumah yang
runtuh adalah rumah yang dibangun tanpa struktur
penguat seperti sloof, kolom, balok ring dari beton
bertulang, material yang tidak memenuhi standar dan
banyak rumah tinggal yang dibangun tanpa mengikuti
peraturan dan konsep desain bangunan tahan gempa
yang ada (Wibowo).
Untuk membantu korban tuna wisma, pemerintah
harus segera memberi bantuan berupa rumah tinggal
yang dapat dibangun secara cepat sehingga korban
dapat kembali beraktifitas dengan normal. Untuk
mengatasi masalah tersebut, maka pada penelitian ini
diusulkan rumah tahan gempa dari beton pracetak.
Sistem pracetak beton mempunyai beberapa
kelebihan seperti mutu dan bahan lebih terjamin karena
proses pembuatan di pabrik dengan control kualitas
pekerjaan yang prima, waktu pemasangan lebih cepat
dan praktis, beton dapat langsung diekspos tanpa perlu
finishing terlebih dahulu. Selain itu,
tidak perlu khawatir bahwa penggunaan elemen precast
tersebut akan mahal, karena mengingat elemen pracetak
bisa diproduksi secara massal dan seragam sehingga
elemen-elemen dalam jumlah besar bisa langsung
dicetak dan dirakit di lapangan untuk membuat suatu
perumahan se-tipe dalam jumlah banyak dalam waktu
singkat. Karena bisa mempercepat waktu pelaksanaan,
maka pasti akan menghemat biaya (Yee, 2001).
Salah satu komponen struktural bangunan adalah
balok. Balok menerima beban lentur yang menyebabkan
keruntuhan tarik dan beban geser yang dapat
menyebabkan keruntuhan getas (britlle). Desain geser
merupakan hal yang sangat penting dalam struktur
beton karena kekuatan tarik beton jauh lebih kecil
dibandingkan dengan kekuatan tekannya. Perilaku balok
beton bertulang pada keadaan runtuh geser sangat
berbeda dengan pada keruntuhan karena lentur. Balok
tersebut langsung hancur tanpa ada peringatan terlebih
dahulu.
Dalam penelitian ini akan digunakan sistem
struktur infill frame, pengertian sistem struktur infilled
frame adalah sistem struktur dimana kontribusi infill
panel (dinding atau panel pengisi rangka)
diperhitungkan dalam menahan beban lateral. Infilled
frame terdiri dari 3 komponen, yaitu rangka
(frame/skeletal structure), infill panel (bagian pengisi)
dan penghubung antara rangka dan infill
panel/pengisinya (Hoenderkamp et al,2005). Sistem
struktur ini dipilih karena banyak konstruksi rangka
gedung pada abad ke-20 ini yang dindingnya (cladding)
sengaja didesain untuk menambah kestabilan dan
kekakuan struktur terhadap beban lateral (D. V. Malick,
1967), sehingga dapat membantu rangka bahkan
mengoptimalkan dimensi rangka.
Download Filel
gempa yang cukup tinggi (puslitbang). Dampak yang
terjadi akibat gempa bumi tersebut adalah jatuhnya
korban jiwa dan keruntuhan sebagian besar bangunan,
khususnya rumah tinggal. Sebagian besar rumah yang
runtuh adalah rumah yang dibangun tanpa struktur
penguat seperti sloof, kolom, balok ring dari beton
bertulang, material yang tidak memenuhi standar dan
banyak rumah tinggal yang dibangun tanpa mengikuti
peraturan dan konsep desain bangunan tahan gempa
yang ada (Wibowo).
Untuk membantu korban tuna wisma, pemerintah
harus segera memberi bantuan berupa rumah tinggal
yang dapat dibangun secara cepat sehingga korban
dapat kembali beraktifitas dengan normal. Untuk
mengatasi masalah tersebut, maka pada penelitian ini
diusulkan rumah tahan gempa dari beton pracetak.
Sistem pracetak beton mempunyai beberapa
kelebihan seperti mutu dan bahan lebih terjamin karena
proses pembuatan di pabrik dengan control kualitas
pekerjaan yang prima, waktu pemasangan lebih cepat
dan praktis, beton dapat langsung diekspos tanpa perlu
finishing terlebih dahulu. Selain itu,
tidak perlu khawatir bahwa penggunaan elemen precast
tersebut akan mahal, karena mengingat elemen pracetak
bisa diproduksi secara massal dan seragam sehingga
elemen-elemen dalam jumlah besar bisa langsung
dicetak dan dirakit di lapangan untuk membuat suatu
perumahan se-tipe dalam jumlah banyak dalam waktu
singkat. Karena bisa mempercepat waktu pelaksanaan,
maka pasti akan menghemat biaya (Yee, 2001).
Salah satu komponen struktural bangunan adalah
balok. Balok menerima beban lentur yang menyebabkan
keruntuhan tarik dan beban geser yang dapat
menyebabkan keruntuhan getas (britlle). Desain geser
merupakan hal yang sangat penting dalam struktur
beton karena kekuatan tarik beton jauh lebih kecil
dibandingkan dengan kekuatan tekannya. Perilaku balok
beton bertulang pada keadaan runtuh geser sangat
berbeda dengan pada keruntuhan karena lentur. Balok
tersebut langsung hancur tanpa ada peringatan terlebih
dahulu.
Dalam penelitian ini akan digunakan sistem
struktur infill frame, pengertian sistem struktur infilled
frame adalah sistem struktur dimana kontribusi infill
panel (dinding atau panel pengisi rangka)
diperhitungkan dalam menahan beban lateral. Infilled
frame terdiri dari 3 komponen, yaitu rangka
(frame/skeletal structure), infill panel (bagian pengisi)
dan penghubung antara rangka dan infill
panel/pengisinya (Hoenderkamp et al,2005). Sistem
struktur ini dipilih karena banyak konstruksi rangka
gedung pada abad ke-20 ini yang dindingnya (cladding)
sengaja didesain untuk menambah kestabilan dan
kekakuan struktur terhadap beban lateral (D. V. Malick,
1967), sehingga dapat membantu rangka bahkan
mengoptimalkan dimensi rangka.
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PERENCANAAN GEDUNG PERPUSTAKAAN 5 ( LIMA ) LANTAI DENGAN PRINSIP DAKTILITAS TINGKAT DUA
Perkembangan dunia ilmu pengetahuan ( science ) semakin cepat setiap
waktu dan akan terus berkembang sesuai dengan kemajuan jaman. Buku
merupakan sumber ilmu pengetahuan yang dapat membuat seseorang menjadi
mengerti akan ilmu pengetahuan, baik itu ilmu sosial maupun ilmu alam.
Memasyarakatkan budaya membaca dan memahami tentang ilmu pengetahuan
merupakan tujuan dari pendidikan nasional untuk meningkatkan Sumber Daya
Manusia ( SDM ) yang sudah lama digalakan oleh Pemerintah, untuk tujuan
tersebut dibutuhkan adanya prasarana penunjang. Prasarana penunjang tersebut
diantaranya adalah gedung perpustakaan.
Kodya Surakarta merupakan suatu kota yang cukup besar dengan
banyaknya penduduk yang membutuhkan suatu perpustakaan pusat kota yang
menyediakan buku-buku referensi untuk pengembangan SDM setiap anggota
masyarakat. Pembangunan perpustakaan pusat kota diharapkan akan dapat lebih
menggugah minat masyarakat kota untuk mempelajari ilmu pengetahuan sesuai
dengan minat dan bakat masing-masing.
Perencanaan gedung perpustakaan pusat kota perlu mempelajari struktur
organisasi suatu perpustakaan modern agar fungsi bangunan gedung tersebut
memenuhi syarat untuk pengembangan dimasa yang akan datang.
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waktu dan akan terus berkembang sesuai dengan kemajuan jaman. Buku
merupakan sumber ilmu pengetahuan yang dapat membuat seseorang menjadi
mengerti akan ilmu pengetahuan, baik itu ilmu sosial maupun ilmu alam.
Memasyarakatkan budaya membaca dan memahami tentang ilmu pengetahuan
merupakan tujuan dari pendidikan nasional untuk meningkatkan Sumber Daya
Manusia ( SDM ) yang sudah lama digalakan oleh Pemerintah, untuk tujuan
tersebut dibutuhkan adanya prasarana penunjang. Prasarana penunjang tersebut
diantaranya adalah gedung perpustakaan.
Kodya Surakarta merupakan suatu kota yang cukup besar dengan
banyaknya penduduk yang membutuhkan suatu perpustakaan pusat kota yang
menyediakan buku-buku referensi untuk pengembangan SDM setiap anggota
masyarakat. Pembangunan perpustakaan pusat kota diharapkan akan dapat lebih
menggugah minat masyarakat kota untuk mempelajari ilmu pengetahuan sesuai
dengan minat dan bakat masing-masing.
Perencanaan gedung perpustakaan pusat kota perlu mempelajari struktur
organisasi suatu perpustakaan modern agar fungsi bangunan gedung tersebut
memenuhi syarat untuk pengembangan dimasa yang akan datang.
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PERENCANAAN STRUKTUR BETON BERTULANG UNTUK HOTEL TUJUH LANTAI (+1 BASEMENT) DENGAN PRINSIP DAKTALITAS PARSIAL DI DAERAH SUKOHARJO (TINJAUAN 2 DIMENSI
Sukoharjo merupakan kabupaten yang tengah berkembang di Propinsi
Jawa Tengah. Hal tersebut mengakibatkan meningkatnya bisnis dan perdagangan
di kabupaten Sukoharjo. Oleh karena itu banyak orang dari luar daerah yang
datang ke Sukoharjo untuk berbisnis maupun mengembangkan usaha yang
dimiliki. Diantara orang-orang tersebut tidak hanya melakukan kegiatannya
dalam sehari, mungkin untuk mengurus bisnisnya diperlukan waktu berhari-hari,
agar kegiatan yang dilakukan tersebut dapat berjalan dengan baik diperlukan
sarana yang memadai dan mendukung. Salah satu sarana yang dibutuhkan
adalah gedung perhotelan.
Gedung perhotelan adalah merupakan tempat untuk peristirahatan atau
penginapan setelah melakukan kegiatan perjalanan, namun dalam
perkembangannya hotel tidak hanya sebagai tempat peristirahatan atau
penginapan tetapi hotel juga dapat digunakan sebagai tempat pertemuan ataupun
rapat dengan rekan bisnis. Berkaitan dengan hal tersebut diatas maka penyusun
mencoba untuk merencanakan gedung perhotelan 7 lantai (+1 basement) di
Sukoharjo.
Salah satu faktor yang paling berpengaruh dalam perencanaan struktur
bangunan bertingkat tinggi adalah kekuatan struktur bangunan, dimana faktor ini
sangat terkait dengan keamanan dan ketahanan bangunan dalam menahan atau
menampung beban yang bekerja pada struktur. Indonesia termasuk negara rawan
dilanda gempa karena terletak dipertemuan Cirkum Pasifik dan Tran Asiatik.
Menurut SNI 03-1726-2002, Sukoharjo termasuk pada wilayah gempa 3 yaitu
merupakan daerah cukup besar kemungkinan terjadinya gempa maka untuk
itulah dalam perencanaan gedung bertingkat tinggi ini harus direncanakan dan
didesain dengan matang agar dapat digunakan sebaik-baiknya, nyaman dan aman
terhadap bahaya gempa bagi pemakai atau penguna struktur gedung.
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Jawa Tengah. Hal tersebut mengakibatkan meningkatnya bisnis dan perdagangan
di kabupaten Sukoharjo. Oleh karena itu banyak orang dari luar daerah yang
datang ke Sukoharjo untuk berbisnis maupun mengembangkan usaha yang
dimiliki. Diantara orang-orang tersebut tidak hanya melakukan kegiatannya
dalam sehari, mungkin untuk mengurus bisnisnya diperlukan waktu berhari-hari,
agar kegiatan yang dilakukan tersebut dapat berjalan dengan baik diperlukan
sarana yang memadai dan mendukung. Salah satu sarana yang dibutuhkan
adalah gedung perhotelan.
Gedung perhotelan adalah merupakan tempat untuk peristirahatan atau
penginapan setelah melakukan kegiatan perjalanan, namun dalam
perkembangannya hotel tidak hanya sebagai tempat peristirahatan atau
penginapan tetapi hotel juga dapat digunakan sebagai tempat pertemuan ataupun
rapat dengan rekan bisnis. Berkaitan dengan hal tersebut diatas maka penyusun
mencoba untuk merencanakan gedung perhotelan 7 lantai (+1 basement) di
Sukoharjo.
Salah satu faktor yang paling berpengaruh dalam perencanaan struktur
bangunan bertingkat tinggi adalah kekuatan struktur bangunan, dimana faktor ini
sangat terkait dengan keamanan dan ketahanan bangunan dalam menahan atau
menampung beban yang bekerja pada struktur. Indonesia termasuk negara rawan
dilanda gempa karena terletak dipertemuan Cirkum Pasifik dan Tran Asiatik.
Menurut SNI 03-1726-2002, Sukoharjo termasuk pada wilayah gempa 3 yaitu
merupakan daerah cukup besar kemungkinan terjadinya gempa maka untuk
itulah dalam perencanaan gedung bertingkat tinggi ini harus direncanakan dan
didesain dengan matang agar dapat digunakan sebaik-baiknya, nyaman dan aman
terhadap bahaya gempa bagi pemakai atau penguna struktur gedung.
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ANALISIS PENAMPANG KOLOM BETON BERTULANG PERSEGI BERLUBANG MENGGUNAKAN PCA COL
Pemasangan pipa pada kolom bangunan
(conduit) banyak ditemukan dalam struktur beton
bertulang. Pemasangan pipa ini dianggap
menguntungkan karena pipa di dalam kolom dapat
dimanfaatkan sebagai saluran listrik, air hujan, air
kotor, dan sebagainya sehingga bangunan akan
terlihat rapi tanpa pipa yang tampak dari luar.
Peraturan beton yang baru (SNI 03-2847-
2002) menyebutkan: Saluran pipa bersama kaitnya,
yang ditanam pada kolom tidak boleh menempati
lebih dari 4% luas penampang yang diperlukan untuk
kekuatan atau untuk perlindungan kebakaran.
Dari uraian di atas dapat disimpulakan
adanya permasalahan untuk memberikan saran-saran
mengenai pemakaian conduit di dalam penampang
kolom mengingat pentingnya elemen kolom dalam
menopang beban bangunan. Tujuan pembahasan
dalam artikel ini adalah mengetahui sejauh mana
pengaruh luas penampang lubang kolom yang
melebihi batas 4% terhadap luas penampang kolom
pada kemampuannya dalam memikul beban struktur
berdasarkan hasil diagram interaksi kolom.
Kekuatan kolom dalam memikul beban
didasarkan pada kemampuannya memikul kombinasi
beban axial (Pu) dan Momen (Mu) secara bersamaan.
Sehingga perencanaan kolom suatu struktur
bangunan didasarkan pada kekuatan dan kekakuan
penampang lintangnya terhadap aksi beban aksial dan
momen lentur. Untuk mempermudah mengetahui
kekuatan penampang kolom biasanya dibuat diagram
interaksi, yaitu suatu grafik daerah batas yang
menunjukkan ragam kombinasi beban aksial dan
momen yang dapat ditahan oleh kolom secara aman
(Wahyudi, 1997).
Pada Diagram Interaksi kolom (lihat Gambar
1), sumbu vertikal menunjukkan beban axial yang
dapat ditahan kolom sedang sumbu horizontal
menunjukkan beban momen yang dapat ditahan oleh
kolom.
Kolom yang mengalami beban axial murni
(Axial Load only) terjadi apabila kolom hanya
menahan beban sentris pada penampangnya (tanpa
eksentrisitas). Pada kondisi ini gaya luar akan ditahan
oleh penampang kolom yang secara matematis
dirumuskan dalam persamaan:
Pn = 0,8 x { 0,85. fc’. (Ag – Ast) + Ast.fy } (1)
dengan
fc’ = Kuat tekan beton yang disyaratkan
(MPa),
Ag = Luas penampang kolom,
Ast = Luas tulangan,
fy = Kuat tarik tulangan baja yang
diijinkan (MPa).
Apabila beban P bergeser dari sumbu kolom,
maka timbul eksentrisitas beban pada penampang
kolom, sehingga kolom harus memikul kombinasi
pembebanan aksial dan momen. Pada kolom yang
mengalami beban eksentris, apabila besarnya beban
aksial dan momen yang ditahan oleh kolom diplotkan
dalam gambar diagram interaksi kekuatan
penampang kolom, maka akan terdapat 4 jenis
kondisi keruntuhan penampang kolom.
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(conduit) banyak ditemukan dalam struktur beton
bertulang. Pemasangan pipa ini dianggap
menguntungkan karena pipa di dalam kolom dapat
dimanfaatkan sebagai saluran listrik, air hujan, air
kotor, dan sebagainya sehingga bangunan akan
terlihat rapi tanpa pipa yang tampak dari luar.
Peraturan beton yang baru (SNI 03-2847-
2002) menyebutkan: Saluran pipa bersama kaitnya,
yang ditanam pada kolom tidak boleh menempati
lebih dari 4% luas penampang yang diperlukan untuk
kekuatan atau untuk perlindungan kebakaran.
Dari uraian di atas dapat disimpulakan
adanya permasalahan untuk memberikan saran-saran
mengenai pemakaian conduit di dalam penampang
kolom mengingat pentingnya elemen kolom dalam
menopang beban bangunan. Tujuan pembahasan
dalam artikel ini adalah mengetahui sejauh mana
pengaruh luas penampang lubang kolom yang
melebihi batas 4% terhadap luas penampang kolom
pada kemampuannya dalam memikul beban struktur
berdasarkan hasil diagram interaksi kolom.
Kekuatan kolom dalam memikul beban
didasarkan pada kemampuannya memikul kombinasi
beban axial (Pu) dan Momen (Mu) secara bersamaan.
Sehingga perencanaan kolom suatu struktur
bangunan didasarkan pada kekuatan dan kekakuan
penampang lintangnya terhadap aksi beban aksial dan
momen lentur. Untuk mempermudah mengetahui
kekuatan penampang kolom biasanya dibuat diagram
interaksi, yaitu suatu grafik daerah batas yang
menunjukkan ragam kombinasi beban aksial dan
momen yang dapat ditahan oleh kolom secara aman
(Wahyudi, 1997).
Pada Diagram Interaksi kolom (lihat Gambar
1), sumbu vertikal menunjukkan beban axial yang
dapat ditahan kolom sedang sumbu horizontal
menunjukkan beban momen yang dapat ditahan oleh
kolom.
Kolom yang mengalami beban axial murni
(Axial Load only) terjadi apabila kolom hanya
menahan beban sentris pada penampangnya (tanpa
eksentrisitas). Pada kondisi ini gaya luar akan ditahan
oleh penampang kolom yang secara matematis
dirumuskan dalam persamaan:
Pn = 0,8 x { 0,85. fc’. (Ag – Ast) + Ast.fy } (1)
dengan
fc’ = Kuat tekan beton yang disyaratkan
(MPa),
Ag = Luas penampang kolom,
Ast = Luas tulangan,
fy = Kuat tarik tulangan baja yang
diijinkan (MPa).
Apabila beban P bergeser dari sumbu kolom,
maka timbul eksentrisitas beban pada penampang
kolom, sehingga kolom harus memikul kombinasi
pembebanan aksial dan momen. Pada kolom yang
mengalami beban eksentris, apabila besarnya beban
aksial dan momen yang ditahan oleh kolom diplotkan
dalam gambar diagram interaksi kekuatan
penampang kolom, maka akan terdapat 4 jenis
kondisi keruntuhan penampang kolom.
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Rabu, 01 September 2010
HYDRAULIC DESIGN OF HIGHWAY CULVERTS
The purpose of this publication is to provide information for the planning and hydraulic design ofhighway culverts and inlet improvements for culverts (Figure I-1). Design methods are included
for special shapes including long-span culverts (Figure I-2). Detailed information is provided on
the routing of flow through culverts. Guidance and reference sources are furnished for
environmental, safety, structural, economic, and other consideration.
The check lists, design charts and tables, and
calculation forms of this publication should provide
the designer with the necessary tools to perform
culvert designs ranging from the most basic culverts
to more complex improved inlet designs (Figure I-3)
is a flowchart of the culvert design procedure
followed in this manual.
The methodology of culvert design presented in this
publication is in a clear, usable format. It is intended
for those with a good understanding of basic
hydrologic and hydraulic methods and with some
experience in the design of hydraulic structures.
The experienced designer is assumed to be able to
understand the variety of flow conditions which are
possible in these complex hydraulic structures and
make appropriate adjustments. The inexperienced
designer and those unfamiliar with hydraulic
phenomena should use this publication with caution.
This publication combines the information and
methodology contained in Hydraulic Engineering
Circular HEC Number 5, Hydraulic Charts for the
Selection of Highway Culverts, HEC Number10,
Capacity Charts for the Hydraulic Design of
Highway Culverts, and HEC Number 13, Hydraulic
Design of Improved Inlets for Culverts with other
more recent culvert information developed by
governmental agencies, universities, and culvert
manufacturers to produce a comprehensive culvert
design publication.
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Highway Hydrology Metric Version
Hydrology is often defined as the science that deals with the physical properties, occurrence, and
movement of water in the atmosphere, on the surface of, and in the outer crust of the earth. This
is an all-inclusive and somewhat controversial definition for there are individual bodies of science
dedicated to the study of various elements contained within this definition. Meteorology,
oceanography, geohydrology, among others, are typical. For the highway designer, the primary
focus is with the water that moves on the earth's surface and in particular that part which
ultimately crosses transportation arterials, i.e., highway stream crossings. A secondary interest is
to provide interior drainage for roadways, median areas, and interchanges.
Hydrologists have been studying the flow or runoff of water over land for many decades, and
some rather sophisticated theories have been proposed to describe the process. Unfortunately,
most of these attempts have been only partially successful not only because of the complexity of
the process and the many interactive factors involved, but also because of the stochastic nature
of rainfall, snowmelt, and other sources of water. Most of the factors and parameters that
influence surface runoff have been defined, but for many, complete functional descriptions of
their individual effects exist only in empirical form. Extensive field data, empirically determined
coefficients, and sound judgment and experience are required for their quantitative analysis.
By application of the principles and methods of modern hydrology, it is possible to obtain
solutions that are functionally acceptable and form the basis for the design of highway drainage
structures. It is the purpose of this manual to present some of these principles and techniques
and to explain their uses by illustrative examples. First, however, it is desirable to discuss some
of the basic hydrologic concepts that will be utilized throughout the manual and to discuss
hydrologic analysis as it relates to the highway stream crossing problem.
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movement of water in the atmosphere, on the surface of, and in the outer crust of the earth. This
is an all-inclusive and somewhat controversial definition for there are individual bodies of science
dedicated to the study of various elements contained within this definition. Meteorology,
oceanography, geohydrology, among others, are typical. For the highway designer, the primary
focus is with the water that moves on the earth's surface and in particular that part which
ultimately crosses transportation arterials, i.e., highway stream crossings. A secondary interest is
to provide interior drainage for roadways, median areas, and interchanges.
Hydrologists have been studying the flow or runoff of water over land for many decades, and
some rather sophisticated theories have been proposed to describe the process. Unfortunately,
most of these attempts have been only partially successful not only because of the complexity of
the process and the many interactive factors involved, but also because of the stochastic nature
of rainfall, snowmelt, and other sources of water. Most of the factors and parameters that
influence surface runoff have been defined, but for many, complete functional descriptions of
their individual effects exist only in empirical form. Extensive field data, empirically determined
coefficients, and sound judgment and experience are required for their quantitative analysis.
By application of the principles and methods of modern hydrology, it is possible to obtain
solutions that are functionally acceptable and form the basis for the design of highway drainage
structures. It is the purpose of this manual to present some of these principles and techniques
and to explain their uses by illustrative examples. First, however, it is desirable to discuss some
of the basic hydrologic concepts that will be utilized throughout the manual and to discuss
hydrologic analysis as it relates to the highway stream crossing problem.
Download File
Introduction to Highway Hydraulics
Highway hydraulic structures perform the vital function of conveying, diverting, or removing surface water from the highway right-of-way. They should be designed to be commensurate with risk, construction cost, importance of the road, economy of maintenance, and legal requirements. One type of drainage facility will rarely provide the most satisfactory drainage for all sections of a highway. Therefore, the designer should know and understand how different drainage facilities can be integrated to provide complete drainage control.Drainage design covers many disciplines, of which two are hydrology and hydraulics. The determination of the quantity and frequency of runoff, surface and groundwater is a hydrologic problem. The design of structures with the proper capacity to divert water from the roadway, remove water from the roadway, and pass collected water under the roadway is a hydraulic problem.
This publication will briefly discuss hydrologic techniques with an emphasis on methods suitable to small drainage areas, since many components of highway drainage (e.g., storm drains, roadside ditches, etc.) service primarily small drainage areas. Fundamental hydraulic concepts are also briefly discussed, followed by open-channel flow principles and design applications of open-channel flow in highway drainage. Then, a parallel discussion of closed-conduit concepts and applications in highway drainage will be presented. The concluding sections include an introduction to energy dissipation, construction, maintenance, and economic issues. In all cases, detailed design criteria and standards are provided primarily by reference, since the objective of this document is to present a broad overview of all the components of highway drainage and to serve primarily as an "Introduction to Highway Hydraulics."
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Highway Hydrology
Hydrology is often defined as the science that addresses the physical properties, occurrence,and movement of water in the atmosphere, on the surface of, and in the outer crust of the earth.
This is an all-inclusive and somewhat controversial definition as there are individual bodies of
science dedicated to the study of various elements contained within this definition. Meteorology,
oceanography, and geohydrology, among others, are typical. For the highway designer, the
primary focus of hydrology is the water that moves on the earth's surface and in particular that
part that ultimately crosses transportation arterials (i.e., highway stream crossings). A
secondary interest is to provide interior drainage for roadways, median areas, and interchanges.
Hydrologists have been studying the flow or runoff of water over land for many decades, and
some rather sophisticated theories have been proposed to describe the process. Unfortunately,
most of these attempts have been only partially successful, not only because of the complexity
of the process and the many interactive factors involved, but also because of the stochastic
nature of rainfall, snowmelt, and other sources of water. Hydrologists have defined most of the
factors and parameters that influence surface runoff. However, for many of these surface runoff
factors, complete functional descriptions of their individual effects exist only in empirical form.
Their qualitative analysis requires extensive field data, empirically determined coefficients, and
sound judgment and experience.
By application of the principles and methods of modern hydrology, it is possible to obtain
solutions that are functionally acceptable and form the basis for the design of highway drainage
structures. It is the purpose of this manual to present some of these principles and techniques
and to explain their uses by illustrative examples. First, however, it is desirable to discuss some
of the basic hydrologic concepts that will be utilized throughout the manual and to discuss
hydrologic analysis as it relates to the highway stream-crossing problem.
In highway engineering, the diversity of drainage problems is broad and includes the design of
pavements, bridges, culverts, siphons, and other cross drainage structures for channels varying
from small streams to large rivers. Stable open channels and stormwater collection,
conveyance, and detention systems must be designed for both urban and rural areas. It is often
necessary to evaluate the impacts that future land use, proposed flood control and water supply
projects, and other planned and projected changes will have on the design of the highway
crossing. On the other hand, the designer also has a responsibility to adequately assess flood
potentials and environmental impacts that planned highway and stream crossings may have on
the watershed.
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HIGHWAY STORMWATER PUMP STATION DESIGN
1.1 NEED FOR STORMWATER PUMP STATIONS
Stormwater pumping stations are necessary for the removal of stormwater from sections of
highway where gravity drainage is impossible or impractical. However, stormwater pumping
stations are expensive to operate and maintain and have a number of potential problems that
must be addressed. Therefore, the use of stormwater pumping stations is recommended only
where no other practicable alternative is available. Alternatives to pumping stations include
siphons, recharge basins, deep and long storm drain systems and tunnels.
1.2 INTENT OF MANUAL
This manual is intended primarily for highway drainage designers and others interested in the
hydraulic design of highway stormwater pump stations. Though some discussion relates to other
engineering disciplines and responsibilities, the information is basic and intended only to
enhance the hydraulic designer’s ability to accommodate other needs and communicate with
designers from other disciplines.
1.3 ORGANIZATION OF MANUAL
This manual is divided into fourteen chapters including this introduction. The general
organization can be classified as follows:
1. Identification and basic concepts (Chapters 2 and 3)
2. Design process (Chapter 4)
3. Design criteria, considerations, and procedures (Chapters 4 through 9)
4. Additional Information (Chapters 10 through 14, and appendices)
1.4 UNIT CONVENTION
The general convention employed in this manual is to present values and dimensions in
System Internationale (SI) units followed by English units in parentheses. Where practicable, the
manual provides equations with unit conversion factors. In this manner, only one equation
appears for a particular operation and the user must select the desired units and unit conversion
factor.
1.4.1 SI versus Metric
System Internationale (SI) units are very specific. Not all metric units are SI. For example,
linear measurements of millimeters and meters are metric and SI, whereas centimeters are metric
but not SI. This manual uses SI units except where noted to conform to industry standards.
1.4.2 Caution on Unit Usage
Most manufacturers in the US develop pumps and pumping equipment in English units. Few
present design data in SI units. The designer should take care when using and quoting units
because some variables that are seemingly dimensionless may have units. Some commonly used
coefficients have dimensions, which, in the strictest sense, should take on different values when
using SI units. These will be noted where appropriate throughout the text.
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Stormwater pumping stations are necessary for the removal of stormwater from sections of
highway where gravity drainage is impossible or impractical. However, stormwater pumping
stations are expensive to operate and maintain and have a number of potential problems that
must be addressed. Therefore, the use of stormwater pumping stations is recommended only
where no other practicable alternative is available. Alternatives to pumping stations include
siphons, recharge basins, deep and long storm drain systems and tunnels.
1.2 INTENT OF MANUAL
This manual is intended primarily for highway drainage designers and others interested in the
hydraulic design of highway stormwater pump stations. Though some discussion relates to other
engineering disciplines and responsibilities, the information is basic and intended only to
enhance the hydraulic designer’s ability to accommodate other needs and communicate with
designers from other disciplines.
1.3 ORGANIZATION OF MANUAL
This manual is divided into fourteen chapters including this introduction. The general
organization can be classified as follows:
1. Identification and basic concepts (Chapters 2 and 3)
2. Design process (Chapter 4)
3. Design criteria, considerations, and procedures (Chapters 4 through 9)
4. Additional Information (Chapters 10 through 14, and appendices)
1.4 UNIT CONVENTION
The general convention employed in this manual is to present values and dimensions in
System Internationale (SI) units followed by English units in parentheses. Where practicable, the
manual provides equations with unit conversion factors. In this manner, only one equation
appears for a particular operation and the user must select the desired units and unit conversion
factor.
1.4.1 SI versus Metric
System Internationale (SI) units are very specific. Not all metric units are SI. For example,
linear measurements of millimeters and meters are metric and SI, whereas centimeters are metric
but not SI. This manual uses SI units except where noted to conform to industry standards.
1.4.2 Caution on Unit Usage
Most manufacturers in the US develop pumps and pumping equipment in English units. Few
present design data in SI units. The designer should take care when using and quoting units
because some variables that are seemingly dimensionless may have units. Some commonly used
coefficients have dimensions, which, in the strictest sense, should take on different values when
using SI units. These will be noted where appropriate throughout the text.
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Hydraulic Engineering Circular No. 22, Third Edition
URBAN DRAINAGE DESIGN MANUAL
This circular provides a comprehensive and practical guide for the design of storm drainage
systems associated with transportation facilities. Design guidance is provided for the design
of storm drainage systems which collect, convey, and discharge stormwater flowing within and
along the highway right-of-way. As such, this circular covers the design of most types of
highway drainage. Two exceptions to this are the design of cross-drainage facilities such as
culverts and bridges, and subsurface drainage design. Guidance for the design of crossdrainage
facilities is provided in HDS-1, Hydraulics of Bridge Waterways,(1) HDS-5, Hydraulic
Design of Highway Culverts,(2) as well as the AASHTO Highway Drainage Guidelines Volume
IV,(3) and Volume VII.(4) Subsurface drainage design is covered in detail in Highway
Subdrainage Design.(5)
Methods and procedures are given for the hydraulic design of storm drainage systems.
Design methods are presented for evaluating rainfall and runoff magnitude, pavement
drainage, gutter flow, inlet design, median and roadside ditch flow, structure design, and storm
drain piping. Procedures for the design of detention facilities and the review of storm water
pump stations are also presented, along with a review of urban water quality practices.
The reader is assumed to have an understanding of basic hydrologic and hydraulic principles.
Detailed coverage of these subjects is available in HDS-2, Hydrology,(6) HDS-4, Introduction
to Highway Hydraulics,(7) Design and Construction of Urban Stormwater Management
Systems,(8) as well as basic hydrology and hydraulic text books.
This document consists of nine additional chapters and four appendices. The nine chapters
cover System Planning, Urban Hydrologic Procedures, Pavement Drainage, Roadside and
Median Channels, Structures, Storm Drains, Stormwater Quantity Control Facilities, Pump
Stations, and Urban Water Quality Practices. Appendixes include: Appendix A, Design
Charts; Appendix B, Gutter Flow Relationship Development; Appendix C, Literature
Reference, and Appendix D, Blank Forms.
Several illustrative design examples are developed throughout the document. By following the
design examples, the reader is led through the design of a complete stormwater management
system. In the main body of the manual, all procedures are presented using hand
computations in both SI and English units.
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This circular provides a comprehensive and practical guide for the design of storm drainage
systems associated with transportation facilities. Design guidance is provided for the design
of storm drainage systems which collect, convey, and discharge stormwater flowing within and
along the highway right-of-way. As such, this circular covers the design of most types of
highway drainage. Two exceptions to this are the design of cross-drainage facilities such as
culverts and bridges, and subsurface drainage design. Guidance for the design of crossdrainage
facilities is provided in HDS-1, Hydraulics of Bridge Waterways,(1) HDS-5, Hydraulic
Design of Highway Culverts,(2) as well as the AASHTO Highway Drainage Guidelines Volume
IV,(3) and Volume VII.(4) Subsurface drainage design is covered in detail in Highway
Subdrainage Design.(5)
Methods and procedures are given for the hydraulic design of storm drainage systems.
Design methods are presented for evaluating rainfall and runoff magnitude, pavement
drainage, gutter flow, inlet design, median and roadside ditch flow, structure design, and storm
drain piping. Procedures for the design of detention facilities and the review of storm water
pump stations are also presented, along with a review of urban water quality practices.
The reader is assumed to have an understanding of basic hydrologic and hydraulic principles.
Detailed coverage of these subjects is available in HDS-2, Hydrology,(6) HDS-4, Introduction
to Highway Hydraulics,(7) Design and Construction of Urban Stormwater Management
Systems,(8) as well as basic hydrology and hydraulic text books.
This document consists of nine additional chapters and four appendices. The nine chapters
cover System Planning, Urban Hydrologic Procedures, Pavement Drainage, Roadside and
Median Channels, Structures, Storm Drains, Stormwater Quantity Control Facilities, Pump
Stations, and Urban Water Quality Practices. Appendixes include: Appendix A, Design
Charts; Appendix B, Gutter Flow Relationship Development; Appendix C, Literature
Reference, and Appendix D, Blank Forms.
Several illustrative design examples are developed throughout the document. By following the
design examples, the reader is led through the design of a complete stormwater management
system. In the main body of the manual, all procedures are presented using hand
computations in both SI and English units.
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ANALISA DAN KOORDINASI SINYAL ANTAR SIMPANG PADA RUAS JALAN DIPONEGORO SURABAYA
Keberadaan persimpangan tidak dapat dihindari pada sistem transportasi perkotaan.
Hal ini pulalah yang terjadi pada kota Surabaya. Sebagai kota terbesar kedua di Indonesia
dengan jumlah penduduk mencapai lima juta jiwa pada siang hari (Agam, 2008), akan timbul
permasalahan pada saat semua orang bergerak bersamaan. Persimpangan pun menjadi salah
satu bagian yang harus diperhatikan dalam rangka melancarkan arus transportasi di
perkotaan. Oleh karena itu, keberadaaanya harus dikelola sedemikian rupa sehingga
didapatkan kelancaran pergerakan yang diharapkan.
Hal yang dapat dilakukan untuk memperoleh kelancaran pergerakan tersebut adalah
dengan menghilangkan konflik atau benturan pada persimpangan. Cara yang dapat digunakan
adalah dengan mengatur pergerakan yang terjadi pada persimpangan. Adapun fasilitas yang
dapat difungsikan adalah lampu lalu lintas (traffic light).
Meski demikian, banyaknya persimpangan yang terdapat di kota besar seperti
Surabaya mampu menimbulkan permasalahan tersendiri. Hal tersebut terjadi pada beberapa
ruas jalan yang memiliki banyak persimpangan, ditambah dengan jarak antar simpang yang
pendek. Permasalahan yang terkadang terjadi adalah kendaaraan yang harus selalu berhenti
pada tiap simpang karena selalu mendapat sinyal merah. Tentu saja hal ini menimbulkan
ketidaknyamanan pengendara, disamping lamanya tundaan yang terjadi.
Kondisi inilah yang terjadi pada Jalan Diponegoro Surabaya yang menjadi objek
studi. Dalam hal ini, Jalan Diponegoro menjadi jalan utama yang diprioritaskan
kelancarannya karena hirarkinya yang merupakan jalan arteri primer dan volumenya yang
lebih besar daripada jalan pendekat lainnya.
Terdapat empat simpang bersinyal yang berdekatan pada ruas tersebut. Keempatnya
adalah simpang antara Jalan Diponegoro dengan Jalan Ciliwung (Simpang I), Jalan
Bengawan (Simpang II), Jalan Musi (Simpang III), dan Jalan Raya Dr Soetomo (Simpang
IV). Adapun jarak antar simpang yang terdapat pada ruas Jalan Diponegoro tersebut adalah
250 meter antara simpang I dan II, 460 meter antara simpang II dan III, dan 220 meter antara
simpang III dan IV. Dengan jarak antar simpang yang dekat, pengendara kerap kali berhenti
pada tiap simpangnya karena terkena sinyal merah.
Untuk itu, perlu dilakukan analisa terhadap koordinasi keempat simpang pada ruas
Jalan Diponegoro tersebut. Penyelesaian yang dapat dilakukan adalah dengan
mengkoordinasikan sinyal lampu lalulintas pada keempat simpang. Perlakuan ini dilakukan
dengan mengutamakan jalur utama yang bervolume lebih besar sehingga dapat menghindari
tundaan akibat lampu merah. Dengan demikian, kelambatan dan antrian panjang pun dapat
diminimalisir.
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Hal ini pulalah yang terjadi pada kota Surabaya. Sebagai kota terbesar kedua di Indonesia
dengan jumlah penduduk mencapai lima juta jiwa pada siang hari (Agam, 2008), akan timbul
permasalahan pada saat semua orang bergerak bersamaan. Persimpangan pun menjadi salah
satu bagian yang harus diperhatikan dalam rangka melancarkan arus transportasi di
perkotaan. Oleh karena itu, keberadaaanya harus dikelola sedemikian rupa sehingga
didapatkan kelancaran pergerakan yang diharapkan.
Hal yang dapat dilakukan untuk memperoleh kelancaran pergerakan tersebut adalah
dengan menghilangkan konflik atau benturan pada persimpangan. Cara yang dapat digunakan
adalah dengan mengatur pergerakan yang terjadi pada persimpangan. Adapun fasilitas yang
dapat difungsikan adalah lampu lalu lintas (traffic light).
Meski demikian, banyaknya persimpangan yang terdapat di kota besar seperti
Surabaya mampu menimbulkan permasalahan tersendiri. Hal tersebut terjadi pada beberapa
ruas jalan yang memiliki banyak persimpangan, ditambah dengan jarak antar simpang yang
pendek. Permasalahan yang terkadang terjadi adalah kendaaraan yang harus selalu berhenti
pada tiap simpang karena selalu mendapat sinyal merah. Tentu saja hal ini menimbulkan
ketidaknyamanan pengendara, disamping lamanya tundaan yang terjadi.
Kondisi inilah yang terjadi pada Jalan Diponegoro Surabaya yang menjadi objek
studi. Dalam hal ini, Jalan Diponegoro menjadi jalan utama yang diprioritaskan
kelancarannya karena hirarkinya yang merupakan jalan arteri primer dan volumenya yang
lebih besar daripada jalan pendekat lainnya.
Terdapat empat simpang bersinyal yang berdekatan pada ruas tersebut. Keempatnya
adalah simpang antara Jalan Diponegoro dengan Jalan Ciliwung (Simpang I), Jalan
Bengawan (Simpang II), Jalan Musi (Simpang III), dan Jalan Raya Dr Soetomo (Simpang
IV). Adapun jarak antar simpang yang terdapat pada ruas Jalan Diponegoro tersebut adalah
250 meter antara simpang I dan II, 460 meter antara simpang II dan III, dan 220 meter antara
simpang III dan IV. Dengan jarak antar simpang yang dekat, pengendara kerap kali berhenti
pada tiap simpangnya karena terkena sinyal merah.
Untuk itu, perlu dilakukan analisa terhadap koordinasi keempat simpang pada ruas
Jalan Diponegoro tersebut. Penyelesaian yang dapat dilakukan adalah dengan
mengkoordinasikan sinyal lampu lalulintas pada keempat simpang. Perlakuan ini dilakukan
dengan mengutamakan jalur utama yang bervolume lebih besar sehingga dapat menghindari
tundaan akibat lampu merah. Dengan demikian, kelambatan dan antrian panjang pun dapat
diminimalisir.
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Minggu, 22 Agustus 2010
Tidal Hydrology, Hydraulics and Scour at Bridges
This manual draws extensively from the results of a Pooled Fund Project "Development of
Hydraulic Computer Models to Analyze Tidal and Coastal Stream Hydraulic Conditions at
Highway Structures." The authors gratefully acknowledge the special efforts of the lead
state, South Carolina Department of Transportation and William Hulbert (formerly SCDOT),
the Pooled Fund Project’s Technical Advisory Panel, and Johnny Morris (formerly FHWA) for
their support and guidance in completing the Pooled Fund Project.
The authors also wish to acknowledge the technical assistance, review, and guidance
provided by Larry Arneson and Joseph Krolak (FHWA), and Scott Douglass (University of
South Alabama) for their efforts in completing this First Edition of Hydraulic Engineering
Circular No. 25 – Tidal Hydrology, Hydraulics, and Scour at Bridges.
The purpose of this manual is to provide guidance on hydraulic analysis for bridges
over tidal waterways. This document includes descriptions of: (1) common physical features
that affect transportation projects in coastal areas, (2) tide causing astronomical and
hydrologic processes, (3) approaches for determining hydraulic conditions for bridges in tidal
waterways, (4) applying the hydraulic analysis results to provide scour estimates. This
document is not intended to provide guidance on coastal surge modeling (modeling that is
used to predict the magnitude of hurricane-produced storm surges based on direct simulation
of hurricane conditions). However, the information provided by other agencies (including
FEMA, NOAA, USACE, States Agencies) on surge conditions is used to estimate the
hydraulic conditions of tidally affected bridges.
By using the methods in this manual, better predictions of bridge hydraulics and scour
in tidal waterways will result. In many cases, simplified tidal hydraulic methods will provide
adequate results. However, when the simplified methods yield overly conservative results,
use of the recommended modeling approaches will provide more realistic predictions and
hydraulic variables and scour.
Location and hydraulic design studies for tidal bridges should be conducted in
accordance with 23 CFR 650A, when applicable. Since this document provides guidance on
the hydraulic analysis of bridges over tidal waterways, the methods described herein can
help assess potential impacts of proposed structures and encroachments on floodplains.
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Hydraulic Computer Models to Analyze Tidal and Coastal Stream Hydraulic Conditions at
Highway Structures." The authors gratefully acknowledge the special efforts of the lead
state, South Carolina Department of Transportation and William Hulbert (formerly SCDOT),
the Pooled Fund Project’s Technical Advisory Panel, and Johnny Morris (formerly FHWA) for
their support and guidance in completing the Pooled Fund Project.
The authors also wish to acknowledge the technical assistance, review, and guidance
provided by Larry Arneson and Joseph Krolak (FHWA), and Scott Douglass (University of
South Alabama) for their efforts in completing this First Edition of Hydraulic Engineering
Circular No. 25 – Tidal Hydrology, Hydraulics, and Scour at Bridges.
The purpose of this manual is to provide guidance on hydraulic analysis for bridges
over tidal waterways. This document includes descriptions of: (1) common physical features
that affect transportation projects in coastal areas, (2) tide causing astronomical and
hydrologic processes, (3) approaches for determining hydraulic conditions for bridges in tidal
waterways, (4) applying the hydraulic analysis results to provide scour estimates. This
document is not intended to provide guidance on coastal surge modeling (modeling that is
used to predict the magnitude of hurricane-produced storm surges based on direct simulation
of hurricane conditions). However, the information provided by other agencies (including
FEMA, NOAA, USACE, States Agencies) on surge conditions is used to estimate the
hydraulic conditions of tidally affected bridges.
By using the methods in this manual, better predictions of bridge hydraulics and scour
in tidal waterways will result. In many cases, simplified tidal hydraulic methods will provide
adequate results. However, when the simplified methods yield overly conservative results,
use of the recommended modeling approaches will provide more realistic predictions and
hydraulic variables and scour.
Location and hydraulic design studies for tidal bridges should be conducted in
accordance with 23 CFR 650A, when applicable. Since this document provides guidance on
the hydraulic analysis of bridges over tidal waterways, the methods described herein can
help assess potential impacts of proposed structures and encroachments on floodplains.
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Kamis, 19 Agustus 2010
Highways in the Coastal Environment
Hydraulic Engineering Circular No. 25June 2008
A technical advisory panel oversaw the development of this document. Members of that panel
were Kevin Bodge, Billy Edge, Dave Henderson, Rick Renna, and J. Richard Weggel.
This is the second edition of HEC-25. This second edition is a new document with a new title.
The authors of the first edition, entitled “Tidal Hydrology, Hydraulics and Scour at Bridges,” were
L.W. Zevenbergen, P.F. Lagasse, and B.L. Edge. This second edition incorporates and
presents more comprehensive discussions of highways in the coastal environment.
A number of faculty and students at the University of South Alabama provided input into this
document including Qin “Jim” Chen, Lauren McNeill, Bret Webb, Caren Reid, Patrick Keith, Joel
Richards, and Jason Shaw.
The majority of this document was written by Scott L. Douglass, Professor of Civil Engineering
at the University of South Alabama. The project manager, Joe Krolak, FHWA Office of Bridge
Technology, provided some significant contributions.
The purpose of this HEC-25 document is to provide guidance for the analysis, planning, designand operation of highways in the coastal environment (HICE). The focus is on roads and
bridges (highways) near the coast that are always, or occasionally during storms, influenced by
coastal tides and waves.
This document is intended to be a reference guidance document for Federal Highway
Administration (FHWA), State Departments of Transportation (SDOT), the American Association
of State Highway and Transportation Officials (AASHTO), consultants to these organizations,
and others.
This is nominally the second edition of HEC-25. The first edition was entitled “Tidal Hydrology,
Hydraulics and Scour at Bridges” and reflected results of a SDOT pooled fund study
investigating coastal scour. This second edition is a completely new document and incorporates
and presents more comprehensive discussions of the coastal environment.
Nationally, there are few transportation (and specifically highway related) documents that focus
on the coastal environment. The existing guidance most similar to this document is a Chapter of
the “Highway Drainage Guidelines” published by AASHTO.1 This HEC-25 HICE document
provides additional details on many of the topics discussed in those AASHTO guidelines.
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Junction Loss Experiments: Laboratory Report Publication No. FHWA-HRT-07-036
The junction loss study described in this report was conducted at the Federal Highway
Administration (FHWA) hydraulics laboratory. Between 1986 and 1992, Chang et al. conducted a
lab study of energy losses through junction access holes, using relatively large-scale (one-quarter
scale) physical models.(1) A preliminary method for determining such losses, based on early results
from that study, was published in the Federal Highway Administration’s (FHWA) Urban Drainage
Design Manual (Hydraulic Engineering Circular No. 22 (HEC 22)).(2) FHWA plans to update HEC
22 and further develop computer software for storm drain design. The need for consistent
technology in FHWA publications and software applications on this subject is urgent. To
accommodate that need and overcome some of the difficulties in estimating energy loss in access
holes, the FHWA’s Office of Bridge Technology initiated this study to validate Roger Kilgore’s
proposed method for computing access hole energy losses. This report will be of interest to
hydraulic engineers involved in storm drain design and to researchers involved in developing
improved storm drain design guidelines. It is being published as a Web document only.
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Administration (FHWA) hydraulics laboratory. Between 1986 and 1992, Chang et al. conducted a
lab study of energy losses through junction access holes, using relatively large-scale (one-quarter
scale) physical models.(1) A preliminary method for determining such losses, based on early results
from that study, was published in the Federal Highway Administration’s (FHWA) Urban Drainage
Design Manual (Hydraulic Engineering Circular No. 22 (HEC 22)).(2) FHWA plans to update HEC
22 and further develop computer software for storm drain design. The need for consistent
technology in FHWA publications and software applications on this subject is urgent. To
accommodate that need and overcome some of the difficulties in estimating energy loss in access
holes, the FHWA’s Office of Bridge Technology initiated this study to validate Roger Kilgore’s
proposed method for computing access hole energy losses. This report will be of interest to
hydraulic engineers involved in storm drain design and to researchers involved in developing
improved storm drain design guidelines. It is being published as a Web document only.
Download File
Senin, 16 Agustus 2010
CONSTRUCTION MATERIALS
This section describes the basic properties
of materials commonly used in construction.
For convenience, materials are
grouped in the following categories:
cementitious materials, metals, organic materials,
and composites. Application of these materials is
discussed in following sections. In these sections
also, environmental degradation on the materials
are described.
Cementitious Materials
Any substance that bonds materials may be
considered a cement. There are many types of
cements. In construction, however, the term cement
generally refers to bonding agents that are mixed
with water or other liquid, or both, to produce a
cementing paste. Initially, a mass of particles coated
with the paste is in a plastic state and may be
formed, or molded, into various shapes. Such a
mixture may be considered a cementitious material
because it can bond other materials together. After
a time, due to chemical reactions, the paste sets and
themass hardens. When the particles consist of fine
aggregate (sand), mortar is formed. When the
particles consist of fine and coarse aggregates,
concrete results.
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of materials commonly used in construction.
For convenience, materials are
grouped in the following categories:
cementitious materials, metals, organic materials,
and composites. Application of these materials is
discussed in following sections. In these sections
also, environmental degradation on the materials
are described.
Cementitious Materials
Any substance that bonds materials may be
considered a cement. There are many types of
cements. In construction, however, the term cement
generally refers to bonding agents that are mixed
with water or other liquid, or both, to produce a
cementing paste. Initially, a mass of particles coated
with the paste is in a plastic state and may be
formed, or molded, into various shapes. Such a
mixture may be considered a cementitious material
because it can bond other materials together. After
a time, due to chemical reactions, the paste sets and
themass hardens. When the particles consist of fine
aggregate (sand), mortar is formed. When the
particles consist of fine and coarse aggregates,
concrete results.
Download File
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