advanced in earthquake engineering applications

First Edition 2008 MOHD. ZAMRI RAMLI, ROZAINA ISMAL & MELDI SUHATRIL 2008

All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical including photocopy, recording, or any information storage and retrieval system, without permission in writing from Universiti Teknologi Malaysia, Skudai, 81310 Johor Darul Tak'zim, Malaysia. Perpustakaan Negara Malaysia Cataloguing-in-Publication Data Advances in earthquake engineering applications / editor Mohd Zamri Ramli, Rozaina Ismail, Meldi Suhatril. ISBN 978-983-52-0571-2 1. Earthquake engineering. 2. Earthquake hazard analysis. I. Mohd Zamri Ramli. II. Rozaina Ismail. III. Meldi Suhatril. IV. Universiti Teknologi Malaysia. Fakulti Kejuruteraan Sivil. 624.1762

Pereka Kulit: MOHD. NAZIR MD. BASRI

Diatur huruf oleh / Typeset by MOHD. ZAMRI RAMLI & RAKAN-RAKAN

Fakulti Kejuruteraan Awam Universiti Teknologi Malaysia

81310 Skudai Johor Darul Ta'zim, MALAYSIA

Diterbitkan di Malaysia oleh / Published in Malaysia by

PENERBIT UNIVERSITI TEKNOLOGI MALAYSIA

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Dicetak di Malaysia oleh / Printed in Malaysia by UNIVISION PRESS

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Contents

CONTENTS

Preface vii

Chapter 1

Development of Seismic Hazard Maps of East Malaysia Azlan Adnan, Hendriyawan, Aminaton Marto, B.Selvanayagam P.N.

1

Chapter 2 Microzonation Study for Putrajaya, Malaysia Azlan Adnan, Hendriyawan; Aminaton Marto, Irsyam, M.

19

Chapter 3 Vulnerability Study of Public Buildings Subjected to Earthquake by ATC-21, ATC-22 And Finite Element Modeling Mohd Zamri Ramli, Azlan Adnan, Suhana Suradi.

35

Chapter 4 Buildings Classification using Applied Technology Council (ATC 21) Mohd Zamri Ramli, Tay Tzer Yong

49

Chapter 5 Seismic Performance of Sultan Azlan Shah Bridge under Low Earthquake Ground Motion Azlan Adnan, Meldi Suhatril, Ismail Mohd Taib

61

Contents

Chapter 6 Seismic Performance of Rapid KL Elevated Span Bridge under Low Earthquake Ground Motion Azlan Adnan, Meldi Suhatril, Ismail Mohd Taib

77

Chapter 7 Analysis of Prestress Concrete Highway Bridges with and Without Rubber Bearing Mohd Zamri Ramli, Azlan Adnan

93

Chapter 8 Predicting of Bridge Condition Based on Seismic Zonation by using Artificial Neural Network Azlan Adnan, Sophia C. Alih, Rozaina Ismail

111

Chapter 9 Database System and Digital Earthquake Evaluation of Buildings Azlan Adnan, Rozaina Ismail

127

Index 145

vii Preface

PREFACE

This book talks about applications of advances earthquake engineering. As we know, more than 6400 people died in the Kobe Earthquake on January 17, 1995. Two to three million people died in earthquakes during the 20th century. More than 240,000 perished in the Tangshan Earthquake in China and 20,000 in the Izmit and Indian earthquakes. And every of us must still remember with 2004 Acheh and 2008 Sinchuan earthquake. This book is intended as a structural analyses guide for practitioners and advanced students. Earthquake engineering is a vast subject and the intention of this book is not to provide a fully comprehensive treatment of all aspects. Rather, it is providing the practicing engineer with an understanding of those aspects of the subject that are important when analyzing structural. Although earthquake does not respect national boundaries, the practice of earthquake engineering does vary significantly between region, and this is reflected in the differing formats and requirements of national seismic codes. The first chapter of this book reviews the process of development of seismic hazard map. The second chapter gives briefed introduction about the development of microzonation study. These first two chapters are important to provide input for seismic design, land use management, and estimation of the potential for liquefaction and landslides. Chapter 3 and 4 discussed how the vulnerability study of building is done using ATC-21, ATC 22 and

viii Preface

finite element modeling. The vulnerability and analysis of performance of the bridge are present in chapter 5 and 6. Chapter 7 introduced the method of modeling structures with and without seismic hazard reduction material such as seismic rubber bearing. Chapter 8 therefore discussed about the technology to do prediction of structure under seismic using artificial neural network. Lastly, chapter 9 introduces special tools to evaluate the buildings using database system.

Mohd Zamri Ramli Rozaina Ismail Meldi Suhatril Faculty of Civil Engineering, Universiti Teknologi Malaysia 2008

1

DEVELOPMENT OF SEISMIC HAZARD MAPS OF EAST MALAYSIA

Azlan Adnan Hendriyawan

Aminaton Marto B. Selvanayagam, P.N.

INTRODUCTION Earthquakes are natural phenomenon which can cause huge losses of life and economy. In recent years, Malaysia is more aware to the seismic effect on their buildings because the tremors were repeatedly felt over the centuries from the earthquake events around Malaysia (SEASEE, 1985). Peninsular Malaysia has felt tremors several times from some of the large earthquakes originating from the intersection areas of Eurasian plate and Indo-Australian plate near Sumatra, and some of the moderate to large earthquakes originating from the Great Sumatran fault. On the other hand, East Malaysia has experienced small to moderate earthquakes from local origin and tremors originating from the southern part of the intersection area of Eurasian and Philippines plates as listed by Surat (2001) and Rosaidi (2001). The 1976 earthquake of magnitude 5.8 in Lahad Datu caused some houses and buildings to develop cracks in the walls. A four storey police complex nearing completion suffered severe structural damage. Several roads in the district were reported to have cracked too, causing damage. Similarly, the 1991 Ranau earthquake of magnitude 5.2 on Richter scale caused extensive damages to a four-storey teachers quarters and were verified unfit

2 Advances in Earthquake Engineering Applications

for occupancy. The earthquake of magnitude 4.8 that occurred on 2 May 2004 near Miri, Sarawak likewise caused some damages to the non-reinforced concrete buildings and developed cracks on the ground (Bernama, 2004). The frequent occurrence of tremors within the country and nearby region seems to suggest that seismic risk in Malaysia is evident. The question now is the level of risk and its regional variation and whether it is necessary to consider seismic factors in the planning and design of structures and/or infrastructures. These questions have so far remained unanswered due to a lack of understanding of seismicity and inadequate seismic data in Malaysia. Hence, the level of seismic risk in Malaysia is still barely known. It is not known if such risk should be considered in future design of structures and/or infrastructures. This is further compounded by the fact that Malaysia is rapidly developing and major installations and high-rise structures are being constructed at a rapid pace. Based on the above facts, the earthquake engineering research is urgently required in order to predict the possibility of earthquakes in the future that can cause damages to the buildings and structures in Malaysia and to find the solutions for mitigating the effects. The engineers have a responsibility to quantify the earthquake risks in Malaysia quantitatively and find the optimal solutions to deal with those effects. This paper presents the development of seismic hazard maps for East Malaysia using total probability theorem. The analysis covers the development of seismotectonic model, the determination of seismic hazard parameters, and the selection of appropriate attenuation relationships for East Malaysia. SEISMOTECTONIC SETTING East Malaysia is located at the triple junction of the Pacific (through the Philippine plate), Indo-Australian and Eurasian Plates (Figure 1.1). The interactions among the plates are very complex


and active. According to the Seismo-Tectonic Map published by Jabatan Penyiasatan Kajibumi Malaysia (JPKM, 1994) the seismicity around this location is affected by the low seismic active level of stable Sunda tectonic plate and moderately active seismic level of Sabah and East Kalimantan (Figure 1.2).

Figure 1.1 Plate tectonic setting of Southeast Asia (after McClay, 2000)

Generally tectonic features that affected East Malaysia can be divided into three classifications, i.e. subduction zone, transform zone and diffuse seismicity zone. The first classification is subduction zone. All of those earthquakes that occurred near convergent boundaries where an oceanic plate is being subducted under an island arc or continent are classified into this zone. This zone is formed due to the movement of Sangihe plate that is


subducting an island of Sulawesi on the north side as shown in Figure 1.3.

Figure 1.2 Seismotectonic setting around East Malaysia (JPKM, 1994)

Figure 1.3 Cross section of North Sulawesi Subduction Fault (Cardwell,

1980)

Legend: Strongly Active: A. Outer Burmese Arc B. Inner Burmese Arc C. Indonesian Arc Moderately Active: D. Shan Plateau E. Sabah and East

Kalimantan Active: F. Irrawaddy/Andaman

Trough Stable: G. Junction South China

Sea and Sunda Shelf


The Sangihe plate is subducting down to more than 300 km on the north side of Sulawesi (Figure 1.3). There are two large earthquakes recorded by National Oceanic and Atmospheric Administration (NOAA), United Stated and International Seismological Catalogue (ISC), United Kingdom occurred in this region. The first one was occurred on 22nd January 1905. The earthquake was located at the longitude of 123.0oE and latitude of 1.0oN. The depth of the earthquake was 90.0 km and magnitude, MS, was 8.4. The second was occurred on 21st December 1939 at the longitude of 123.0oE and latitude of 0oN and magnitude, MS, of 8.6. The depth of the earthquake was 150 km. The second classification is transform zone. Transform zone is a terminology for earthquakes that occurred on boundary between two lithospheric plates that are sliding past one another (transform plate boundary). The shallow crustal faults such as Palu-Koro, Walanae or Paternoster (Sulawesi), and Melange (Java) faults can be classified into this zone. Figure 1.4 depicts the location of the shallow crustal faults. The Palu-Koro fault has long been established and mapped as a traversing fault zone across the Sulawesi Island. It roughly divided into two halves, i.e. West and East Sulawesi (Bemmelen, 1949; Brouwer, 1947). The largest earthquake around this region was occurred on 19th May 1938 at the longitude of 123.0oE and latitude of 1oS and magnitude, MS, of 7.9. The latest big earthquake was occurred on 19th October 2001. The earthquake was located at the longitude of 123.91oE and latitude of 4.1oS and magnitude, MS, was 7.5. The third classification is diffuse seismic zone. All earthquakes that occur in areas where seismicity is not associated with a single fault or fault type are classified into this zone. This zone is found in Batui, Poso, Mamuju Sulu, Tarakan Basin, and Kutai-Mahakam Basin source zones. The detail of these faults system is shown in Figure 1.4.


Figure 1.4 Fault sources in Borneo Island (McClay, 2000) REGIONAL SEISMICITY The primary seismicity database used for this study was compiled primarily from four sources:

1. Earthquake listings held by National Earthquake Information Center (NEIC), U.S. Geological Survey (USGS) of the United State.

2. International Seismological Center (ISC), United Kingdom. 3. Malaysian earthquake listing prepared by the Malaysian

Meteorological Service. 4. Pacheco and Sykes catalogue (1992).

The combined catalogues cover areas from 105oE to 125oE longitude and from 10oS to 10oN latitude and include 7039 earthquake events occurred during 108 years period of observation (1897-2004). The location of earthquake epicenter during that period of observation is shown in Figure 1.5.


Figure 1.5 Distribution of epicenters around project Location Some analyses have been performed to the earthquake catalogues as to obtain the reliable earthquake data. The processes are as follows:

1. Choosing a consistent magnitude for SHA, and then the other magnitude scales are converted to this magnitude scale. In this research, a moment magnitude, Mw, was chosen as a measurement to quantify the size of the earthquake. Other types of magnitude in the catalogues were then converted to Mw by using an appropriate formula.

2. Declustering the earthquake data in the catalogues for separating main shock and accessory shock events in order to obtain independent earthquake data. The analysis was performed using time and distance windows criteria proposed by Gardner and Knopoff (1974). The algorithm eliminated more than 50% of earthquake data.

3. Adjusting the length of the statistical time window in order to improve estimates of parameters using completeness analysis method proposed by Stepp (1973). Based on the result, the earthquake events with magnitude less than 6.0 are


completely reported only during the most recent 41 year interval or since 1964, and for events greater than or equivalent 6.0 are completely reported for the whole of 104-year sample interval.

SEISMIC SOURCES MODELS Identification and characterization seismic sources are the first step to analyze seismic hazard. In this stage, seismic source zones are identified including all potential seismic sources capable of generating significant ground motion at the site. A seismic source represents a region of the earths crust where the characteristics of earthquake activity are recognized to be relatively different than those of the adjacent crust. The source geometries were constructed based on earthquake spatial distributions and regional tectonic setting of East Malaysia. Generally, the seismic source model can be divided into three classifications, i.e. North Sulawesi Subduction (NSS) zone, shallow crustal (SC) zone, and background zone. The seismic source models are divided into 15 fault sources and one background source. The fault sources are North Sulawesi Subduction zone (zone 1, 2), Palu-Koro (zone 3, 4, 5, 6), Sulu (zone 7), Tarakan Basin (zone 8), Kutai-Mahakam Basin (zone 9), Walanae (zone 10, 11, 12), Melange (zone 13, 24), and Mamuju (zone 15). The background source was used in this analysis to accommodate uncertainty associated with unknown faults around site region. The seismic source model used in this study can be seen in Figure 1.6. The fault source zones within radius of 500 km from East Malaysia are considered in the analysis. At farther radius, amplitudes of incoming seismic shear waves can be considered small in affecting the site location.


Figure 1.6 Seismic source models for East Malaysia. The NSS was investigated by plotting the spatial distribution of earthquakes around Sulawesi using the regional seismicity data recorded since 1900. A plot of seismicity around NSS can be seen in Figure 1.7. Due to the sparse of epicentral data, NSS is divided into two sections i.e. zone 1 and zone 2. The hypocentral profile of NSS is shown in Figures 1.8. The profiles reveal downward dipping zones of seismicity that mark the subsurface location of the Sangihe plate. Based on the profile, earthquake sources for North Sulawesi can be modelled as an interface and intraslab source zones with 7o and 61o of dip angles, respectively. Based on these dip angles and the focal depth of focus, NSS were divided into Megathrust zone (interface) and Benioff zone (intraslab). This model is consistent with the model of Sangihe Plate as presented by Cardwell et al (1980).


Figure 1.7 Earthquake spatial distributions

Figure 1.8: The hypocentral profiles of NSS


SEISMIC HAZARD PARAMETERS Characterization of seismicity at particular site or region is commonly expressed in seismic hazard parameters. Seismic hazard parameters are needed for fully describing earthquake activity within the earth crust in a certain region. There are three parameters that are most commonly considered in seismic hazard assessment, i.e. a-b parameter, recurrence rate, and maximum size of future earthquakes for each source. Usually, temporal distribution of earthquakes is assumed to follow frequency-magnitude relationship proposed by Gutenberg-Richter (G-R) (1954). Three methods for assessing seismic hazard parameters were used in this research; i.e., Least Square (LS), Weichert (1980), and Kijko & Sellevoll (KS) (1989). The results show that the seismicity b-values in this study are within the range 0.7 to 1.2 which can be considered in the normal range of b-values. The results are shown in Figure 1.9. ATTENUATION RELATIONSHIPS One of the critical factors in seismic analysis is to obtain or to select appropriate attenuation relationship. This formula, also known as ground motion relation, is a simple mathematical model that relates a ground motion parameter (i.e. spectral acceleration, velocity and displacement) to earthquake source parameter (i.e. magnitude, source to site distance, mechanism) and local site condition (Campbell, 2003). Since there is no attenuation function derived for Malaysia region, therefore several attenuation relationships that consider appropriate according to mechanism that likely to occur in Malaysia region from previous researcher were selected. There has been a number of attenuation relations derived in the last two decades since the record of ground motions becomes more available. In general, they are categorized according to tectonic environment (i.e. subduction zone and shallow crustal earthquakes) and site condition.


1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

5.0 6.0 7.0 8.0

Magnitude

N(M

>mo)

Data

Least Square

Weichert

KS

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

5.0 5.5 6.0 6.5 7.0 7.5 8.0

Magnitude

N(M

>mo)

Data

Least Square

Weichert

KS

(a) Palu-Koro b) Other shallow crustal

1.00E-07

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5

Magnitude

N(M

>mo)

Data

Least Square

Weichert

KS

1.00E-07

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5

Magnitude

N(M

>mo)

Data

Least Square

Weichert

KS

(c) N-S Megathrust d) N-S Benioff

Figure 1.9 Recurrence relationship chart for East Malaysia


There are several attenuation relationships derived for subduction zone earthquake, which are commonly used, such as Crouse (1991), Youngs (1997), Atkinson and Boore (1997), Petersen (2004), whereas attenuation relationships, which were developed by Campbell (1997, 2003), Sadigh et al. (1997), Toro (1997), are frequently used to estimate ground motion for shallow crustal earthquakes. Most of the attenuation functions were developed using empirical method. Therefore, the limitation of the function will depend on the quality of strong motion data such as quantity and the distribution of parameters of attenuation function such as magnitude, depth, distance and peak acceleration. Usually attenuation relationships are derived for near source earthquakes; consequently, most of the attenuation relationships have a distance limit. In this study, three attenuation functions are used in seismic analysis. Campbell (2003) attenuation is used for calculating distant earthquakes while Sadigh et al. (1997) and Boore et al. (1997) for short distance earthquakes (less than 100 km). LOGIC TREE Logic trees (Power et al., 1981; Kulkarni et al., 1984; Coppersmith and Youngs, 1986) are used in this study in order to allow uncertainty in selection of models for attenuation, recurrence rate, and maximum magnitude to be considered. In this study, attenuation model of Campbell (2003), Sadigh et al (1997), and Boore et al (1997) are assigned a relative likelihood of 0.33 each. The recurrence rates calculated according to the method of Least Square, Kijko & Sellevoll (1989) and that of Weichert (1980) are considered equally likely to be correct. At final level, different relative likelihoods are assigned to the maximum magnitude. The logic tree model is illustrated in Figure 1.10.


Figure 1.10 Simple logic tree for incorporation of model uncertainty THE RESULTS OF ANALYSIS The hazard calculations were performed for several combinations of attenuation functions, seismic hazard parameters, and maximum magnitudes using total probability theory as proposed by Cornell (1968). The result of each analysis is then multiplied by the relative likelihood of its combination of branches in the logic tree. In order to develop macrozonation maps of East Malaysia, the procedure is then applied for every grid (or site) spacing of 0.5 degrees in latitude and longitude around East Malaysia. The results can be seen in Figures 1.11 to 1.12.


Figure 1.11 Peak ground acceleration (PGA) maps for 500 year

Figure 1.12 Peak ground acceleration (PGA) maps for 2,500 year


CONCLUSION Two macrozonation maps representing 10% and 2% probability of exceedance (PE) in 50 years ground motions for East Malaysia have been developed in this study. The results show the ground motions across the East Malaysia range between 60 and 120 gals and between 160 and 220 gals for 10% and 2% PE in 50-year hazard levels, respectively. The hazard levels show the peak ground acceleration contours increase from the west to the east of East Malaysia. REFERENCES Atkinson, G.M. and Boore, D.M. (1997). Some Comparisons

Between Recent Ground Motion Relations. Seismological Research Letters. Vol. 68. No. 1.

Bernama. (2004). Earthquake Tremors Felt in Miri, Bintulu. Malaysian News National Agency. 2 May 2004.

Boore, D.M., Joyner, W.B., and Fumal, T.E. (1997). Equation for Estimating Horizontal Response Spectra and Peak Acceleration from Western North America Earthquakes: A Summary of Recent Work. Seismological Research Letters, Vol. 68, No. 1, January/February 1997, pp. 128-153.

Brouwer, H.A. (1947). Geological explorations in Celebes summary of results. p. 1-64. In Brouwer, H.A. (ed.), Geological explorations in the island of Celebes. North Holland Publishing Company, Amsterdam.

Campbell, K.W. (1997). Empirical Near-source Attenuation Relationships for Horizontal and Vertical Components of Peak Ground Acceleration, Peak Ground Velocity and Pseudo-absolute Acceleration Response Spectra. Seismological Research Letters. Vol. 68.

Campbell, K.W. (2003). Prediction of strong ground motion using the hybrid empirical method and its use in the development of ground-motion (attenuation) relations in Eastern North


America. Bulletin of the Seismological Society of America. Vol. 93, pp. 10121033.

Cardwell, R.K.I., Isacks, B.L., and Karig, D.E. (1980). The Spatial Distribution of Earthquakes, Focal Mechanism Solutions and Subducted Lithosphere in the Philippine and Northeastern Indonesian Islands. In Hayes, D.E. (ed) The Tectonic and Geology Evolution of South East Asian Seas and Islands. American Geophysical Union Monograph, 23, 1-35.

Coppersmith, K.J., and Youngs, R.R. (1986). Capturing Uncertainty in Probabilistic Seismic Hazard Assessments with Intraplate Tectonic Environments. Proceeding, 3rd U.S. National Conference on Earthquake Engineering. Charleston, South Carolina. Vol. 1, pp. 301-312.

Cornel, C.A. (1968). Engineering Seismic Risk Analysis. Bulletin of the Seismological Society of America. Vol 58, No. 5: 1583-1606.

Crouse, C.B. (1991). Ground Motion Attenuation Equation for Earthquake on the Cascadia Subduction Zone. Earthquake Spectra, Vol. 7, No. 2.

Gardner, J.K., and Knopoff, L. (1974). Is the Sequence of Earthquakes in Southern California, with Aftershocks removed, Poissonian? Bulletin of the Seismological Society of America, Vol. 64, No. 5, 1974, pp. 1363-1367.

2

MICROZONATION STUDY FOR PUTRAJAYA, MALAYSIA

Azlan Adnan Hendriyawan

Aminaton Marto Irsyam, M.

INTRODUCTION Earthquake is one of the most devastating natural disasters on the earth. Generally, the effects of strong earthquakes are caused by ground shaking, surface faulting, liquefaction, and less commonly, by tsunamis. Although it is impossible to prevent earthquakes from happening, it is possible to mitigate the effects of strong earthquake shaking and to reduce loss of life, injuries and damages. The most effective way to reduce disasters caused by earthquakes are to estimate the seismic hazard and to disseminate this information for used in improved building design and construction so that the structures posses adequate earthquake resistant capacity. Geotechnical factors often exert a major influence on damage patterns and loss of life in earthquake events. For example, the localized patterns of heavy damage during the 1985 Mexico City and 1989 Loma Prieta earthquakes provide illustrations of the importance of understanding the seismic response of deep clay deposits and saturated sand deposits. The pronounced influence of local soil conditions on the characteristics of the observed earthquake ground motions also can be seen during 1957 San Francisco Earthquake. Even in one city, however, building


response and damage were varying significantly due to variation of soil profiles in the city. In other countries, several attempts have been made to identify their effects on earthquake hazards related to geotechnical factors in the form of maps or inventories. Mapping of seismic hazard at local scales to incorporate the effects of local geotechnical factors is called microzonation. Microzonation for seismic hazard has many uses as mentioned by Finn et al. It can provide input for seismic design, land use management, and estimation of the potential for liquefaction and landslides. It also provides the basis for estimating and mapping the potential damage to buildings. Putrajaya is a planned city and a federal territory that acts as a federal government administration centre of Malaysia. Therefore, there are a lot of investments and assets that should be protected against earthquake hazard in Putrajaya such as high rise and monumental buildings. This paper presents the results of microzonation study for developing microzonation maps for Putrajaya. GROUND RESPONSE ANALYSIS In this study, ground response analysis was performed using one-dimensional shear wave propagation method (1-D analysis). 1-D method is based on assumption that all boundaries are horizontal and that the response of a soil deposit is predominantly caused by shear wave propagating vertically from the underlying bedrock. Although the soil layers are sometimes inclined or bent, they are regarded as horizontal in most cases. Furthermore, the length of a layer is infinite compared with its thickness. It is thus practical to model them as 1-D horizontal layers. Analytical and numerical procedures based on this concept, incorporating linear approximation to nonlinear soil behavior, have shown reasonable agreements with field observations in a number of cases. The ground response analysis should consider the nonlinearity of soil behavior to provide reasonable results. There are two


approaches to include the effect of nonlinearity of soil material into the analysis: equivalent linear and nonlinear approaches. Equivalent linear models imply that the strain will always return to zero after cyclic loading, and since a linear material has no limiting strength, failure cannot occur. The nonlinear of soil behaviors are approximated by determining the values that consistent with the level of strain induced in each layer. The equivalent linear approach is incapable of representing the changes in soil stiffness those actually occur during the earthquake. It also means that it cannot be used directly for problems involving permanent deformation or failure. An alternative approach is to analyze the actual nonlinear response of a soil deposit using direct numerical integration in the time domain. The advantages of nonlinear method are: (1) the stiffness of an actual nonlinear soil changes over the duration of large earthquake, such high amplification levels that occur in equivalent linear approach, will not develop in the field; and (2) nonlinear method can be formulated in terms of effective stresses to allow modeling of the generation, redistribution, and eventual dissipation of excess pore pressure during and after earthquake shaking. In this study, the ground response analyses were performed using nonlinear approach. The analyses were carried out using program NERA, which stands for Nonlinear Earthquake Response Analysis. This program use soil model proposed by Iwan and Mroz to model nonlinear stress-strain curves of soil. DYNAMIC SOIL PROPERTIES Ground response analysis requires profile of dynamic soil parameters such as maximum shear modulus, Gmax or shear wave velocity, VS and damping, . This parameter can be obtained from field dynamic tests or by converting from static field tests using empirical formula. Numerous researchers have investigated the relationship between maximum shear modulus or shear wave velocity and N-values of Standard Penetration Test (SPT). Most of


the studies were performed in the 1970s in Japan. Since then, some similar studies have been reported in the United States. Some of the correlations were compiled by Barros. In this research, the static parameters from SPT test were converted into VS by using formula proposed by Ohta & Goto and Imai & Tonouchi. In order to verify the formulas, the seismic down-hole tests were performed on several locations and the results were then compared to the results from empirical correlations. A figure 2.1 shows the comparison of shear wave velocity, VS, obtained from empirical correlation and seismic down-hole tests. It can be seen in the figure, the empirical formulas are relatively reliable to predict VS from NSPT values.

SITE CLASSIFICATION Site classification analyses were performed by using 14 soil data in Putrajaya. For each data, the soil dynamic properties are calculated by using formulas proposed by Ohta & Goto and Imai & Tonouchi. The results were summarized in Figure 2.2. The classification of a particular site was determined by referring three specifications: 1997 UBC/2000 IBC, Eurocode 8, and Bray and Rodriguez-Marek. Based on the existing data, the soil in Putrajaya can be classified as SD and SE in accordance with 2000 IBC as shown in Table 2.1.


Figure 2.1 The result of seismic down-hole test

0.0

10.0

20.0

30.0

40.0

0 100 200 300 400VS (m/sec.)

Dep

th (m

)

0.0

10.0

20.0

30.0

40.0

0 100 200 300 400VS (m/sec.)

Dep

th (m

)

Figure 2.2 Soil dynamic properties for Putrajaya

Site Class SD Site Class SE


RESULTS OF 1-D ANALYSIS Shear wave propagation analyses were performed for all existing soil data to obtain peak acceleration and amplification factor at the surface. Two hazard levels were used in the analysis to represent 10% and 2% Probability Exceedance (PE) in design time period of 50 year or correspond to return period of approximately 500 and 2,500 years, respectively. These hazard levels were calculated using total probability theorem as proposed by Cornel. Based on our previous study, the peak ground accelerations for Putrajaya are 0.073g (73.4 gal) and 0.149g (149 gal) for 500 and 2,500 year return periods of ground motions, respectively. The seismic hazard map of Peninsular Malaysia for those two hazard levels can be seen in Figure 2.3.

Table 2.1 Soil Classification of Putrajaya

Soil Classification No. Location VS (m/s)

Tn (sec.) 2000 IBC

[15]

EC8 [16]

BR 1997 [17]

1 PJ-1 213.40 0.47 D C C-2 2 PJ-2 167.12 0.73 E D C-3/E-1 3 PJ-3 278.68 0.35 E C C-1 4 PJ-4 267.36 0.49 D C C-2 5 PJ-5 345.75 0.29 D C C-1 6 PJ-6 278.20 0.48 D C C-2 7 PJ-7 211.00 0.58 D C C-3/E-1 8 PJ-8 193.78 0.60 D C C-3/E-1 9 PJ-9 195.54 0.49 D C C-2 10 PJ-10 214.75 0.77 D C C-3/E-1 11 PJ-11 304 0.39 D C C-2

12 PJ-12 205 0.63 D C C-3/E-1

13 PJ-13 322 0.36 D C C-2

14 PJ-14 341 0.59 D C C-3/E-1


Figure 2.3 Seismic hazard maps of Peninsular Malaysia (site class SB) Four time histories were used in the analysis: Synth-1, Synth-2, Synth-3, and Synth-4. Synth-1 and Synth-2 represent ground motion for 500 years return period, while Synth-3 and Synth-4

TR=500 yr

TR=2500 yr


represent for 2,500 years return period. The time histories used in the analysis can be seen in Figure 2.4.

-0.08-0.06-0.04-0.02

00.020.040.060.08

0 50 100 150 200Time (sec)

Acc

eler

atio

n (g

a) synth-1

-0.1

-0.05

0

0.05

0.1

0 10 20 30 40 50Time (sec)

Acc

eler

atio

n (g

b) synth-2

-0.2

-0.1

0

0.1

0.2

0 25 50 75 100 125 150Time (sec)

Acc

eler

atio

n (g

c) synth-3

-0.15-0.1

-0.050

0.050.1

0.150.2

0 20 40 60 80 100Time (sec)

Acc

eler

atio

n (g

d) synth-4

Figure 2.4 Time histories used in ground response analysis

TR=2500 yr

TR=2500 yr

TR=500 yr

TR=500 yr


The results of acceleration and amplification factors at surface of Putrajaya were summarized in Tables 2.2 and 2.3, respectively. The amplification factors show the ratio between acceleration at bedrock and at surface. Generally, the amplification factors for 500 years return period are higher than 2,500 years return period. The effects of using different time histories can be seen in Figures 2.5 and 2.6 for 500 and 2,500 years return periods of ground motions, respectively. The results indicate that the selection of appropriate time histories is one of the most critical in ground response analysis.

Table 2.2 Results of 1-D analyses for Putrajaya

PSA (g's) No. Location

Soil

Type Synth-1 Synth-2 Synth-3 Synth-4

1 PJ-1 SD 0.168 0.143 0.236 0.270

2 PJ-2 SE 0.144 0.128 0.297 0.260

3 PJ-3 SE 0.201 0.185 0.348 0.337

4 PJ-4 SD 0.197 0.162 0.366 0.337

5 PJ-5 SD 0.174 0.168 0.319 0.315

6 PJ-6 SD 0.134 0.118 0.182 0.193

7 PJ-7 SD 0.160 0.141 0.250 0.315

8 PJ-8 SD 0.173 0.153 0.225 0.285

9 PJ-9 SD 0.157 0.149 0.213 0.258

10 PJ-10 SD 0.137 0.129 0.234 0.225

11 PJ-11 SD 0.173 0.119 0.271 0.297

12 PJ-12 SD 0.163 0.147 0.281 0.288

13 PJ-13 SD 0.175 0.129 0.270 0.307

14 PJ-14 SD 0.155 0.146 0.186 0.196

Response spectra at the surface for Putrajaya can be seen in Figures 2.7 to 2.8. The predominant periods of the spectra generally occur in the range 0.2 - 0.8 second. It also can be seen in the figures, the frequency content of the spectrum is relatively not


much different. In other hand, the figures show that the frequency content of the spectrum is more affected by the stiffness of the soil. According to the figures, soft soil deposits produce greater proportions of long period (low frequency) motions than stiff soil.

Table 2.3 Results of 1-D analyses for Putrajaya (cont.)

Amplification factor

No. Location Soil

Type Synth-1 Synth-2 Synth-3 Synth-4

1 PJ-1 SD 2.30 1.95 1.58 1.81

2 PJ-2 SE 1.98 1.75 1.99 1.75

3 PJ-3 SE 2.76 2.54 2.33 2.26

4 PJ-4 SD 2.69 2.22 2.46 2.26

5 PJ-5 SD 2.39 2.29 2.14 2.11

6 PJ-6 SD 1.84 1.61 1.22 1.29

7 PJ-7 SD 2.20 1.93 1.68 2.12

8 PJ-8 SD 2.36 2.10 1.51 1.91

9 PJ-9 SD 2.15 2.04 1.43 1.73

10 PJ-10 SD 1.87 1.77 1.57 1.51

11 PJ-11 SD 2.37 1.63 1.82 2.00

12 PJ-12 SD 2.24 2.01 1.89 1.93

13 PJ-13 SD 2.40 1.77 1.81 2.06

14 PJ-14 SD 2.12 2.00 1.25 1.32

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0.05 0.08 0.10 0.13 0.15 0.18 0.20

Acceleration (g's)

Dep

th (k

m)

Synth-1Synth-2

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0.05 0.08 0.10 0.13 0.15 0.18 0.20

Acceleration (g's)

Dep

th (k

m)

Synth-1Synth-2

Figure 2.5 1-D analysis for 500 years return period



0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0.10 0.15 0.20 0.25 0.30

Acceleration (g's)D

epth

(km

)

Synth-3Synth-4

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0.10 0.15 0.20 0.25 0.30

Acceleration (g's)

Dep

th (k

m)

Synth-3Synth-4

Figure 2.6 1-D analysis for 2500 years return period

The results of site response analysis at several points were used to develop contour map of surface acceleration and amplification factor for 500-years and 2,500-years return periods. The iso-acceleration contour maps for Putrajaya are shown in Figures 2.9 to 2.10, while the contour of amplification factors can be seen in Figures 2.11 to 2.12. According to the figures, the accelerations at the surface of Putrajaya range between 13% g (130 gal) and 19% g (190 gal) for 10% PE in 50-year hazard levels and between 22% g (220 gal) and 34% g (340 gal) for 2% PE in 50-year hazard levels. The amplification factors for those two hazard levels range between 1.5 and 2.6. Generally, the peak accelerations and amplifications factors contours occur around Precinct 4.

0.010

0.100

1.000

0.0 1.0 2.0 3.0 4.0Period (second)

Spec

tral

Acc

eler

atio

n (g

)

Synth-1Synth-2

0.01

0.10

1.00

0.0 1.0 2.0 3.0 4.0Period (second)

Spec

tral

Acc

eler

atio

n (g

)

Synth-1Synth-2

a) Site Class SD b) Site Class SE

Figure 2.7 Response spectra at surface for 500 years return period



0.001

0.010

0.100

1.000

10.000

0.0 1.0 2.0 3.0 4.0Period (second)

Spec

tral

Acc

eler

atio

n (g

)

Synth-3Synth-4

0.01

0.10

1.00

10.00

0.0 1.0 2.0 3.0 4.0Period (second)

Spec

tral

Acc

eler

atio

n (g

)

Synth-3Synth-4

a) Site Class SD b) Site Class SE

Figure 2.8 Response spectra at surface for 2500 years return period

a) Synth-1 (b) Synth-2

Figure 2.9 Contour of acceleration at surface for 500 years return period

(PGA=0.073 g)


a) Synth-3 (b) Synth-4

Figure 2.10 Contour of acceleration at surface for 2500 years return period (PGA=0.149 g)

a) Synth-1 (b) Synth-2 Figure 2.11 Contour of amplification factor for 500 years return period

(PGA=0.073 g)


a) Synth-3 (b) Synth-4 Figure 2.12 Contour of amplification factor for 2500 years return period

(PGA=0.149 g) SUMMARY AND CONCLUSION This paper has described the microzonation study for Putrajaya in Peninsular Malaysia. Ground response analyses were performed using 1-D shear wave propagation analysis. The analysis was performed for two hazard levels that represent 500 and 2,500 years return periods of earthquake. Four time histories were used in the analysis to represent ground motion for 500 years (Synth-1 and Synth-2) and 2,500 years (Synth-3 and Synth-4) return periods. In this study, the analysis was performed using nonlinear approach in order to consider the actual nonlinear response of a soil deposit. The results of site response analysis at several points were used to develop microzonation maps of Putrajaya for 500 and 2500-years return periods. Four microzonation maps were produced in this research that can be used as input for seismic design, land use management, and estimation of the potential for liquefaction and landslides.


The results of ground response analysis also show that both of time histories and local soil conditions (soil properties and stratigraphy) are critical to the results of ground response analysis. Generally, time histories affect the amplitude of spectral acceleration, whilst the soil conditions (stiffness, stratigraphy, ground water level) influence the frequency content of the spectrum. Therefore, these two subjects should be considered and determined carefully in ground response analyses. REFERENCES Hu, Y.X. (1996). Earthquake Engineering. London: E & FN Spon. Bray, J. D., Seed, R. B., Cluff, L. S., Seed, H. B. (1994).

Earthquake Fault Rupture Propagation through Soil. Journal of Geotechnical Engineering, American Society of Civil Engineers. Vol. 120, No. 3: 543-561.

Seed, H.B., Chaney, R.C., and Pamucku, S. (1991). Foundation Engineering Handbook. New York: Van Nostrand Reinhold.

Finn, W.D.L., Onur, T., Ventura, C.E. (2004). Microzonation: Developments and Applications. In: Ansal, A ed. Recent Advances in Earthquake Geotechnical Engineering and Microzonation. Netherlands: Kluwer Academic Publisher. 3-26.

Kramer, S. L. (1996). Geotechnical Earthquake Engineering. New Jersey: Prentice-Hall.

Bardet, J.P. and Tobita, T. (2001). NERA-A Computer Program for Nonlinear Earthquake site Response Analyses of Layered Soil Deposits. Department of Civil Engineering University of Southern California.

Iwan, W. D. (1967). On A Class of Models for The Yielding Behavior Of Continuous And Composite Systems. Journal of Applied Mechanics, ASME. Vol. 34: 612-617.

Mrz, Z. (1967). On The 'Description of Anisotropic Work hardening. Journal of Mechanics and Physics of Solids. Vol. 15: 163-175.


Barros, J.M.C. (1994). Factor Affecting Dynamic Properties of Soil. Report, University of Michigan.

Ohta, Y. and Goto, N. (1978). Empirical shear wave velocity equations in terms of characteristic soil indexes. Earthquake Engineering Structural Dynamic. Vol. 6:167-187.

Imai, T. and Tonouchi, K. (1982). Correlation of N-value with S-Wave Velocity and Shear Modulus. Proceeding, 2nd European Symposium on Penetration Testing. Amsterdam. Pp. 57-72.

Ohsaki, Y. and R. Iwasaki. (1973).On dynamic shear moduli and Poisson's ratio of soil deposits. Soils and Foundations. Vol. 13, No.:61-73.

Seed, H.B., I.M. Idriss, and I. Arango. (1983). Evaluation of Liquefaction Potential Using Field Performance Data. J. Geotech. Eng., ASCE. Vol. 109, No. 3: 458-482.

Building Seismic Safety Council. (1998). 1997 Edition NEHRP Recommended Provisions for the Development of Seismic Regulations for New Buildings, FEMA 302/303. Part 1 (Provisions) and Part 2 (Commentary). Developed for the Federal Emergency Management Agency. Washington, DC.

International Code Council. (2000). International Building Code 2000. International Code Council. International Conference of Building Officials. Whittier, CA, and others.

3

VULNERABILITY STUDY OF PUBLIC BUILDINGS SUBJECTED TO

EARTHQUAKE BY ATC-21, ATC-22 AND FINITE ELEMENT MODELING

Mohd Zamri Ramli

Azlan Adnan Suhana Suradi

INTRODUCTION ATC21 and ATC22 are handbooks in the FEMA series: (Rapid Visual Screening of Buildings for Potential Seismic Hazard: A Handbook, (ATC, 1988). The handbook has descriptions and illustrations of building types that will be helpful to the engineer in determining the age, building type, and the need for evaluation of the building. The purpose of evaluation is to know how the building performed. In ATC21, the evaluations are performed fast and relatively inexpensive (without detailed analysis for potential hazardous buildings). There is no structural analysis calculations are performed in this evaluation (Figure 3.1). The evaluation only takes 15-30 minutes per building includes inspection, data collection, and decision-making process. In ATC22, the methodology is centred on a set of question one set for each of fifteen model building types that is designed to uncover the flaws and weaknesses of the building. The engineer addresses each statement and determines whether it is true or false. True statements identify conditions that are acceptable. False Statements identify issues or concerns that need further investigation. In dealing with the statements that have been found


to be false, the further analyses are required to identify the problem.

Figure 3.1 ATC-21 form for Mahkamah Labuan


MODELING AND ANALYSIS In order to analyze the seismic performance of the buildings, a single main frame was chosen for modelling in finite element analysis. The finite element software, SAP2000 was used to analyse the structures through a linear dynamic analysis. The analyses were carried for four intensities of seismic load, i.e. 0.05g, 0.10g, 0.15g, and 0.20g. Three analysis methods were applied for the model, i.e. Free Vibration Analysis, Response Spectra Analysis and Time Histories Analysis. The response spectra analyses used UBC94 code for S2 soil. Data recorded from El Centro Earthquake in 1940 was used in Time histories analysis. From the Free Vibration Analysis, the natural period (s), frequency (Hz), angular frequency, and mode shapes were determined. For each building, four mode shapes were analyzed. From Response Spectra Analysis, maximum axial force, shear and maximum moment were determined. The results were compared to static analysis to define the differences between static and dynamic analyses. The maximum allowable axial force, shear and moment for each element of the buildings were compared with the maximum design capacity to determine the capability of each building to retain different capacity of earthquake load. LOAD CASES i) Static Linear Analysis Load Case

1. LC1 WL1,2,3,4 = Dead + Live + Wind 1,2,3,4 2. LC2 = Static EQ 3. LC1 LC2 WL1,2,3,4 = Dead + Live + Static EQ + Wind

1,2,3,4 Wind load (CP3: Chapter V: Part 2) Basic Wind Speed


V1 = WL1 = 20 m/s V2 = WL2 = 30 m/s V3 = WL3 = 40 m/s V4 = WL4 = 50 m/s

Design Wind Speed, Vs = V. S1. S2. S3

Where : V = Basic wind speed S1 = Topography factor S3 = Factor from ground roughness, building size, and height above ground S3 = Statistical factor

Dynamic pressure, q = 0.613 Vs 2 (N/m2 and m/s) Static Earthquake (UBC 97) Seismic Dead Load, W W = Total structure dead load + partition + 25% floor live load Building Period, T

43

nta hCT = where: 0.035 for steel moment frames

Ct = 0.030 for concrete moment frames 0.030 for eccentric braced frames 0.020 for all other buildings hn = the height of the building in feet

Design Base Shear, V V = max { min [ 2.5 Ca.I.W / R , Cv.I.W / R.T ], 0.11Ca.I.W, 0.82 Z.Nv.I.W / R }

Where : W = Seismic dead load T = Building period I = Seismic Importance Factor (UBC Tab 5-1) R = Response Modification Coef. (UBC Tab 5-2) Cv = Numerical coefficient dependent on the soil conditions at the site and regional seismicity


(UBC Tab 5-3) Ca = Another seismic coefficient dependent on the soil conditions at the site and regional seismicity (UBC Tab 5-4)

Soil Profile Types , S1, S2 and S3, (UBC Tab 5-5) Seismic sources type , (UBC Tab 5-6) Z = Seismic zone factor (Figure - Map Malaysia) Na = Near sources factor (UBC Tab 5-7) Nv = Near sources factor zone 4 (UBC Tab 5-8)

Distribution of Lateral Force, Fx

=

= ni

ii

xxtx

hw

hwFVF

1

))((

If T > 0.7 sec. : Ft = 0.07TV 0.25V If T 0.7 sec. : Ft = 0.0

ii. Dynamic Linear Analysis Load Case LC3 = Dead Load (slab) + Spec. 0.05g, 0.10g, 0.15g, 0.20g

Figure 3.2 Response Spectrum Analyses (RSA) UBC 94


iii. Dynamic Time History Analysis: Load Case LC4 = Dead Load + Live Load + TH 0.05g, 0.10g, 0.15g, 0.20g Time History Analysis (THA) (May 18,1940 El Centro-Figure 3.3)

Figure 3.3 Time History Analysis (THA) (May 18,1940 El Centro) STUDY CASE - MAHKAMAH, LABUAN Mahkamah Labuan is an 11 story concrete building was located at Labuan city. Based on built drawing document, the building is a concrete moment resisting frame (Type 8). The building consists of government offices. The elevation of the frame can be seen in Figure 3.4. FREE VIBRATION ANALYSIS (FVA) The mode shapes and time period of the building come from the Free Vibration Analysis (FVA). Table 3.1 shows the buildings natural period and frequency for the free vibration analysis. The first 4 modes are selected in this analysis.


Figure 3.4 Frame model of Mahkamah Labuan building

Table 3.1 Natural period and frequency of Mahkamah Labuan

Mode Shape

Time Period, T (sec.)

Frequency, f (Hz)

Angular Frequency,

1 2 3 4

0.52516 0.15919 0.09709 0.06958

1.90418 6.28180 10.29972 14.97195

11.96433 39.46972 64.71506 90.3016

Referring to Table 3.1, the natural period for mode shape 1 (0. 52516s) is the highest among the other mode shapes and will be used for further analysis. Mode shape 2 indicates 0. 15919s, while mode shape 3 and 4 indicate 0.09709s and 0.06958s respectively. According to UBC formula (T=Cthn3/4), where Ct = 0.030 for concrete moment frames, and hn = the height of the building in feet, natural period of the Mahkamah Labuan building is equal to 0.76s by calculation. The time period for this building is 0.52516 sec (Mode Shape 1). The maximum spectral acceleration curve suitable on that site comes from Palu Koru Fault, Philippine. Figure 3.5 shows that, the design acceleration for this building is equivalent to be 0.09g.


Figure 3.5 Spectral Acceleration for building Mode Shape1 Time Period (Palu Koro Fault)

Table 3.2 Dynamic amplification factor

Note : D < 1 No response

D = 1 Static D > 1 Dynamic Table 3.2 shows the dynamic amplification factor for Mahkamah Labuan based on previous Tawau and Bintulu earthquake. It clearly shows that the analysis of the building needs further analysis on dynamic. This is because the dynamic amplification factor exceeds the static value (D=1), which is 4.46 for Tawau and 1.73 for Bintulu respectively


STATIC AND DYNAMIC LINEAR ANALYSIS Shear and moment capacity for beams in Mahkamah Labuan is equal to 182 kN and 238 kNm respectively. Referring to the output analysis as been summarized in Figure 3.6, the maximum shear force, Vmax in beam under static analysis had exceeded the beam capacity itself. Under load case 1 (LC1) and wind load (20-50 km/hr), Vmax ranges from 847-875 kN. These values increased when LC1 and load case 2 (LC2) being considered together with the same wind load. For these cases Vmax ranges from 1,103-1,130 kN. Besides, for the all load case, maximum moment, Mmax has also exceeded the moment capacity. Mmax ranges from 1,215-2,219 kNm. It shows that under all cases, the beam is not sufficient to resist the maximum shear force and moment under static loading.

(a) Static Linear Analysis on Beam

0

100

200

300

400

500

600

0 20 40 60Basic Wind Speed, v (m/s)

Shea

r, V

(kN)

DL+LL+WL DL+LL+EQ+WL Shear Capacity (b) Static Linear Analysis on Beam

0500

1000150020002500


Mom

ent,

M (k

Nm

)

DL+LL+WL DL+LL+EQ+WL Moment Capacity

Figure 3.6 Shear (a) and Moment (b) at Beam Element (Static Load)


Response Spectrum Analysis of Beam

0.00

50.00

100.00

150.00

200.00

250.00

300.00

0.00 0.05 0.10 0.15 0.20 0.25

Intensity (g)

Shea

r, V

(kN

)

Max. Shear Shear Design Capacity

0.14

Response Spectrum Analysis of Beam

0.00

100.00

200.00

300.00

400.00

500.00

0.00 0.05 0.10 0.15 0.20 0.25

Intensity (g)

Mom

en (k

N-m

m)

Max. Momen Momen Design Capacity

0.07

(a)

(b)

Figure 3.7 Shear (a) and moment (b) at beam element

Design capacity can be made to find the level of safety of the element due to the various loading. Figure 3.7 shows the level of safety for beam in term of shear and moment due to the dynamic linear analysis (RSA). It shows that the element can sustain shear up to 0.14g and 0.07g for moment. For columns in Mahkamah Labuan, axial force, shear and moment capacity is equal to 5,712 kN, 314 kN and 860 kNm respectively. Referring to the output analysis as been summarized in Figure 3.8, it can be seen that the maximum axial force (Amax),


shear force (Vmax), and moment (Mmax) for load case 3 (LC3) under static analysis had exceeded the column capacity. But for load case 1 (LC1), Vmax and Mmax are still lower compare than design capacity itself except for Amax.

(a) Static Linear Analysis on Column

0

2,000

4,000

6,000

8,000

10,000

12,000


Axia

l, A (k

N)

DL+LL+WL DL+LL+EQ+WL Axial Capacity

(b) Static Linear Analysis on Column

0

100

200

300

400

500

600

700

800


Shea

r, V

(kN)

DL+LL+WL DL+LL+EQ+WL Shear Capacity

(c) Static Linear Analysis on Column

0200400600800

1,0001,2001,4001,6001,800


Mom

ent,

M (k

Nm)

DL+LL+WL DL+LL+EQ+WL Moment Capacity

Figure 3.8 Axial Force (a), Shear (b) and Moment (c) on Column (under Static Load)


Figure 3.9 shows the Amax, Vmax, and Mmax curve for column element due to the dynamic linear analysis (RSA). It clearly presents that; all internal forces have the lower value compare that design capacity (for Intensity less than 0.20g).

(a) Response Spectrum Analysis of Column

0.00

1,000.00

2,000.00

3,000.00

4,000.00

5,000.00

6,000.00

0.00 0.05 0.10 0.15 0.20 0.25

Intensity (g)

Axi

al, A

(kN

)

Axial Design Capacity Max. Momen

(b) Response Spectrum Analysis of Column

0.0050.00

100.00

150.00

200.00

250.00300.00350.00

0.00 0.05 0.10 0.15 0.20 0.25

Intensity (g)

She

ar, V

(kN)

Shear Design Capacity Max. Shear

(c) Response Spectrum Analaysis of Column

0.00

200.00

400.00

600.00

800.00

1,000.00

0.00 0.05 0.10 0.15 0.20 0.25

Intensity (g)

Mom

en, M

(kN-

mm

)

Momen Design Capacity Max. Moment

Figure 3.9 Axial (a), shear (b) and moment (c) at column element


CONCLUSIONS Based on ATC21, the study findings show that the selected buildings on the inspection sites has Structural Score less then 2, which indicates critical score and need further investigation. This building are also classify by soft story building but not for highrise building. Due to that result, the building is evaluated in detail using ATC22. Through ATC22, the building system and components are investigated thoroughly. Building components are organized into the following subsystem: vertical elements resisting horizontal loads (i.e., moment resisting frames, shear walls and braced frames), horizontal elements resisting lateral loads (i.e., diaphragms), foundations, and the connections between subsystems. The study shows that, the buildings system is not critical to earthquake load. The buildings show concrete deterioration and have insufficient condition in vertical elements. These include insufficient column tie spacing, stirrups spacing, beam bar splices and joint eccentricities, which could be risky during earthquake. The connections between subsystems are adequate. In detail, some procedures indicate that need further investigation using computer model. The Linear static and dynamic analysis is performed to investigate more about the building characteristics and performance. The result shows that, almost all cases, the beam and column is not sufficient to resist the maximum shear force and moment under static and dynamic loading. It is suggested that the beam element need further investigation using non linear response spectrum analysis.


REFERENCES Azlan Adnan (1998). Low Intensity Earthquake Effects on Steel

Girder Bridge. Universiti Teknologi Malaysia : Tesis Ph.D. Balkema, A.A, Rotterdam and Brookfield (1992). Proceedings of

the tenth World Conference on Earthquake Engineering. Madrid, Spain Volume 4.

British Standards Institusion (1982). Guide To Selection And Use Of Elastomeric bearings For Vibration Isolation Of Buildings~BS6177 :1982. BSI Ltd.: London

Derham, C.J. (1983) Proceedings, Natural Rubber For Earthquake Protection Of Buildings And Vibration Isolation, Proc., International Conference, Kuala Lumpur. Direct Art Co: Kuala Lumpur.

4

BUILDINGS CLASSIFICATION USING APPLIED TECHNOLOGY COUNCIL

(ATC 21)

Mohd Zamri Ramli Tay Tzer Yong

INRODUCTION Every earthquake provides new lessons for the earthquake engineering profession. Most naturally occurring earthquakes are related to the tectonic nature of the earth. Such earthquakes are called tectonic earthquakes. Earthquake is a shake in earth crust that causes of a sudden high energy that release from the earth. This energy maybe causes of a tectonic force in the earth crust. The earth crust is made from a cold and fragile rock and it is different from the layer under it where it is hotter than earth crust. The crack earth crust will wreck and form to piece of rock. This piece of rock will collide each other and cause a pressure that produce a shake and known as earthquake. This shake will produce a seismic wave that can be transforming to kinetic force and next will cause damage to structure when it cant absorb or control this kinetic energy. The method to absorb and control the kinetic force before it damage the structure is equipped the structure with seismic isolator. This paper describes the ATC 21. The method whereby buildings can be rapidly identified via a sidewalk survey from the exterior as seismically acceptable or potentially seismically hazardous. In generally, a Structural Score which consists of a series of scores and modifiers based on building attributes that


can be seen from the street. The Structural Score S is related to the probability of the building sustaining life-threatening damage should a severe earthquake in the region occur. A low S score suggests that the building requires additional study by a professional engineer experienced in seismic design (further investigation) and a high S score indicates that the building is probably adequate. Finally, a location map of Putrajaya Precint 1 is developed to show all buildings weather its need ATC 21 or ATC 22. PROBLEM STATEMENT Earthquake is one of the disasters that occur in many countries and make a serious damage especially to the structure, but also to loss of life and destruction of property because of the collapse structure of high-density people in it. It does happen maybe cause of the structure didnt have any preparation and protection from earthquake. So we have to make an preliminary analysis using Applied Technology Council (ATC 21) to minimize the structures damages in building. OBJECTIVES

a. Classification for buildings uses Applied Technology Council (ATC 21) at Putrajaya Precint 1.

b. To determine how effectiveness Applied Technology Council (ATC 21) during earthquake against the structure of a building.

c. To provide location map of Putrajaya Precint 1 to shows the classifications of various types of buildings were needs ATC 21 and ATC 22


METHODOLOGY The analysis has been made using ATC 21 in the FEMA series: (Rapid Visual Screening of Buildings for Potential Seismic Hazard: A Handbook, (ATC, 1988). The handbook has descriptions and illustrations of building types that will be helpful to the engineer in determining the age, building types and the need for evaluation of the building. In evaluation we want to know how the building performed. In ATC 21, the evaluations are performed fast and relatively inexpensive without detailed analysis for potential hazardous buildings. In this evaluation is without performing structural analysis calculations. The inspection, data collection and decision-making process typically will occur at the building site only takes an average of 15 to 30 minutes per building (30 minutes to one hour if access to the interior is available). Figure 4.1 shows the several steps in collection data, planning and performing a rapid screening of potentially seismically hazardous buildings for classification of building using with Applied Technology Council (ATC 21). RESULT AND DISCUSSION A copy of the Data Collection Form for NEHRP Map Areas 1,2 Low is shown in Figure 4.2. The form has been designed to be filled out in a smooth progressive manner with a minimum of writing. A discussion of how structure hazard scores and modifiers of the Rapid Screening Procedure method were developed is presented in the Data Collection Form. For figure 4.3 is shows a example of Data Collection Form for Building Block E3 Kementerian Pengajian Tinggi Malaysia. The Structural Score is got only 1.9 marks. From the result is shown buildings Structural Score, S is less than 2. Then the seismic performance of that building may not be meet modern seismic criteria and the building should be investigated further.


Figure 4.1 Methodology of the study

Determining Structural Score, S

Choosing A Location For Classification Example : Precint 1, Wilayah Persekutuan Putrajaya

Building Identification Information

Sidewalk Survey From The Exterior

Start

ATC 21 ATC 22

Prepare the Location Plan of Presint 1, Wilayah Persekutuan Putrajaya with ATC 21 and ATC 22

End

Conclusion

Selection And Review Of Data Collection Forms

Walking around and sketching buildings (Elevations and Plan)


Figure 4.2 Example of data collection form (NEHRP Map Areas 1,2 Low)

There have so many types of buildings in this analysis Applied

Technology Council (ATC 21). The types of buildings have government building, school, quarter, commercial building, public assembly, telecom and hotel. Table 4.1 is shows the 37 number of building use analysis ATC 21 at Precint 1, Putrajaya. Form the table, the government buildings were built up on 1997 years and floor high is between 3 floors to 13 floors.


Table 4.1Buildings information use for ATC 21

Nos Building Code

Building Name Nos Of Stories

Year of Build

1 C1 Jabatan Perkhidmatan Awam 10 1997 2 C2 Jabatan Perkhidmatan Awam 8 1997 3 C3 Jabatan Peguam Negara 8 1997 4 C4 Kem. Sains Teknologi & Alam Sekitar 8 1997 5 C5 Kem. Sains, Teknologi Dan Invorsi 8 1997 6 C6 Jabatan Perangkaan Malaysia 8 1997 7 C7 JKR Wilayah Persekutuan Putrajaya 8 1997 8 C10 Dewam Serbaguna 8 1997 9 D1 Kem. Keselamatan Dalam Negeri 10 1997 10 D2 Kementerian Dalam Negeri 7 1997 11 D3 Kementerian Sumber Manusia 7 1997 12 D4 Kementerian Sumber Manusia 7 1997 13 D5 Kementerian Pengangkutan Malaysia 6 1997 14 D6 Badan Pencegah Rasuah 6 1997 15 D7 Jab Kemajuan Islam Msia (JAKIM) 7 1997 16 D8 Audiotorium 3 1997 17 E1 Kementerian Kesihatan Malaysia 6 1997 18 E2 Kementerian Pelajaran Malaysia 9 1997 19 E3 Kementerian Pengajian Tinggi Msia 8 1997 20 E4 & 5 Kem.Tenaga, Air Dan Komunikasi 6 1997 21 E6 Kementerian Kesihatan Malaysia 6 1997 22 E7 Kementerian Kesihatan Malaysia 10 1997 23 E8 Kementerian Pelajaran Malaysia 8 1997 24 E9 Kementerian Pelajaran Malaysia 8 1997 25 E10 Kementerian Kesihatan Malaysia 6 1997 26 E11 Kementerian Pelajaran Malaysia 13 1997 27 E12 Kementerian Pelajaran Malaysia 9 1997 28 E13 Kementerian Pelajaran Malaysia 7 1997 29 E14 Kementerian Pelajaran Malaysia 7 1997 30 E15 Kementerian Pelajaran Malaysia 6 1997 31 S1 Pejabat Sekolah Sultan Alam Shah 3 1999 32 S2 Kelas Bijak Sek. Sultan Alam Shah 4 1999 33 S3 Kuarters Sekolah Sultan Alam Shah 4 1999 34 P1 Alamanda Parkson 1 1999 35 T1 Pejabat Telekom 4 1999 36 M1 Masjid Putrajaya 3 1999 37 H1 Shangri La Hotel 5 1999


Table 4.2 Results from analysis ATC 21 Nos Building Code Modifiers Structural Score Types Of ATC 1 C1 HR, VI 1.9 ATC 22 2 C2 HR, PI 2.4 ATC 21 3 C3 HR, PI 2.4 ATC 21 4 C4 HR, PI 2.4 ATC 21 5 C5 HR, PI 2.4 ATC 21 6 C6 HR 2.9 ATC 21 7 C7 HR 2.9 ATC 21 8 C10 SC 2.4 ATC 21 9 D1 HR 2.9 ATC 21 10 D2 - 3.4 ATC 21 11 D3 - 3.4 ATC 21 12 D4 - 3.4 ATC 21 13 D5 - 3.4 ATC 21 14 D6 - 3.4 ATC 21 15 D7 - 3.4 ATC 21 16 D8 - 3.4 ATC 21 17 E1 VI 2.4 ATC 21 18 E2 HR, VI, PI 1.4 ATC 22 19 E3 HR, VI 1.9 ATC 22 20 E4 & 5 VI 2.4 ATC 21 21 E6 VI 2.4 ATC 21 22 E7 HR, VI 1.9 ATC 22 23 E8 HR, VI 1.9 ATC 22 24 E9 HR, VI 1.9 ATC 22 25 E10 VI 2.4 ATC 21 26 E11 HR, VI, PI 1.4 ATC 22 27 E12 HR, VI, PI 1.4 ATC 22 28 E13 VI 2.4 ATC 21 29 E14 VI 2.4 ATC 21 30 E15 VI 2.4 ATC 21 31 S1 PI 2.9 ATC 21 32 S2 - 3.4 ATC 21 33 S3 - 3.4 ATC 21 34 P1 SC 2.4 ATC 21 35 T1 LHC 2.4 ATC 21 36 M1 SC 2.4 ATC 21 37 H1 VI 2.4 ATC 21 Notes : HR - High Rise SC-Short Column VI-Vertical Irregularity LHC- Large Heavy Cladding PI-Plan Irregularity


There have 8 number of building from total buildings analysis get the low value or less than 2 marks for Structural Score. So, this buildings need to use ATC 22 for further investigation. Figure 4.4 is shows the Percentage of Total 37 number Buildings Analysis in ATC 21 And ATC 22. From the result, we can say that 72.5 % of buildings are in seismically good condition building at Precint 1. There are only 27.5 % of buildings are considering as hazardous building.

72.5%

27.5%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

ATC - 21 ATC - 22

ATC

Perc

enta

ge

Figure 4.4 Percentage from total buildings analysis In ATC 21 and

ATC 22 Figure 4.5 is shows the Percentage Of Government Buildings Analysis in ATC 21 And ATC 22. There have 30 number of government building for this classification analysis. From the result, 73.3 % of government buildings are in seismically good condition building. There are only 26.7 % of buildings are considering as hazardous building.


73.3%

26.7%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

ATC - 21 ATC - 22

ATC

Perc

enta

ge

Figure 4.5 Percentage of government buildings analysis in ATC 21

and ATC 22

Figure 4.6 is shows the Percentage of High Rise Buildings Analysis in ATC 21 And ATC 22. There have 15 number of buildings is 8 stories and taller. From the result, 46.7 % of high rise buildings are in seismically good condition building and 53.3 % of high rise buildings are consider as hazardous building.

46.7%

53.3%

42.0%

44.0%

46.0%

48.0%

50.0%

52.0%

54.0%

ATC - 21 ATC - 22

ATC

Per

cent

age

Figure 4.6 Percentage Of High Rise Buildings Analysis In ATC 21

And ATC 22


Figure 4.7 is shows the Location map indicated the buildings cover by ATC 21 and ATC 22. The location map shown 29 buildings are under ATC 21 and 8 buildings are under ATC 22.

Figure 4.7 Location map indicated the buildings cover by ATC 21 and ATC 22

CONCLUSIONS From the study in this project, the conclusions that can be drawn from study are as follows:

1. The building with calcify under Applied Technology Council (ATC 21) have a less risk of damage when the earthquake occurs compare than the building were calcify under ATC-22.


2. Analysis Applied Technology Council (ATC 21) as an effectives tool to classify the building, the fastest tool to analyse the building, cheaper in cost and easy to use.

3. From the results, 72.5 % of buildings in analysis ATC 21and only have 27.5 % of buildings need to use ATC 22 for further investigation.

This study can be applied to whole part of Putrajaya in the future. The local authority can used this classification map to make decisions related to the maintenance job for the building and also for prevention actions. REFERENCE Federal Emergency Management Agency, Rapid Visual

Screening Of Buildings For Potential Seismic Hazards : A Handbook, April 1988

Supporting Documentation (second edition) (FEMA 155), Rapid Visual Screening of Buildings for Potential Seismic Hazards, September 2000.

ATC-21-T, Rapid Visual Screening of Buildings for Potential Seismic Hazards Training Manual, April 30, 1996

5

SEISMIC PERFORMANCE OF SULTAN AZLAN SHAH BRIDGE UNDER LOW EARTHQUAKE GROUND MOTION

Azlan Adnan

Meldi Suhatril Ismail Mohd Taib

INTRODUCTION In recent years, Malaysia is more aware of the seismic effect on their structures because the tremors were repeatedly felt over the centuries from the earthquake events around Malaysia. Most bridges in Malaysia do not take earthquake loadings into structural design consideration. Therefore the seismic structural vulnerability is very important in order to recognize the performance of the bridges. The seismic analysis for bridges will be conducted as linear and nonlinear problems. In this analysis, Sultan Azlan Shah Bridge in Perak which consists of 5 spans (360 meters) was modeled using two dimensional and three dimensional concepts. The site specific analysis will be performed to determine the earthquake loading (e.g. surface time history and design response spectrum) using borehole data. Design response spectrum will be constructed using IBC2000 modification. The seismic analyses conducted were vibration analysis, time history analysis, response spectrum analysis and damage inelastic analysis. Free vibration analysis presented the periods and mode shapes of the structure while time history and response spectrum analyses considered the applied forces on the deck and piers. Damage inelastic analysis


showed the critical part of the bridge structural failure under several peak ground accelerations (PGA). It can be concluded that Sultan Azlan Shah Bridge is safe under earthquake loading when subjected to local site effect of surface acceleration at 0.161g. The bridge started to show initial cracking at 0.25g and collapsed at 0.32g. RESEARCH OBJECTIVES The overall objective of this phase of the study was to evaluate the seismic response of Sultan Azlan Shah Bridge with the emphasis on the two and three-dimensional effects of ground excitation. Among the objectives are; (i) To perform 2D and 3D modelling analysis to investigate the

seismic response of Sultan Azlan Shah Bridge in the longitudinal direction;

(ii) To determine the time history at surface and construct design response spectrum for Sultan Azlan Shah Bridge; and

(iii) To determine the seismic response of the bridge under earthquake ground motion at different intensity levels, from the initial failure stage up to the collapse level. At this stage, the results would be able to show the critical portions of the bridge under different earthquake ground motions (PGA).

BACKGROUND

Most bridges in Malaysia do not take into account earthquake loadings in the structural design consideration, even though the effects of earthquake are often felt in peninsular Malaysia. Thus, the effects cannot be completely ignored, especially for critical structures such as bridges. In this paper, the seismic performance of Sultan Azlan Shah Bridge in Perak was investigated.


Sultan Azlan Shah Bridge is the main bridge in Perak which crosses the Perak river. The bridge is a segmental prestressed box girder concrete bridge which has 5 spans bridge and is approximately 360 meters long and 41.5 feet (12.5 meters) wide and will be analyzed to withstand earthquake and all other anticipated loads. It consist of five spans supported by 4 intermediate piers and two abutments (Figure 5.1)

Figure 5.1 Elevation of Sultan Azlan Shah Bridge

Sultan Azlan Shah Bridge is a concrete segmental box girder which has different depth for every segment. Figure 5.2 shows the cross section of Sultan Azlan Shah Bridge.

Figure 5.2 Deck cross section of Sultan Azlan Shah Bridge


LOCAL SITE EFFECT ANALYSIS Soil data were collected from existing soil investigation (SI) of the bridge. The shear wave velocity (VS) were obtained by converting the N-SPT value from Standard Penetration Test to shear wave velocity using empirical formula proposed by Ohsaki and Iwasaki (1973), Imai and Tonouchi (1982) and by averaging those two formulas. Based on analysis, the VS-30 of BH-7 is 262 m/s, respectively. Based on these results, generally the site can be classified as stiff soil or site class D (SD) in accordance with 1997 UBC. Based on macrozonation study (Figure 5.3), the peak ground acceleration (PGA) at the bedrock for 500-year return period of earthquake is 0.073g (73 gal). The results of analysis can be seen in Figures 5.4. Generally, the accelerations at the bedrock were amplified on the surface in the range of 2.2-2.4. The predominant periods of the spectra generally occur in the range of 0.3 0.8 second. Time history at the surface can be seen at the Figure 5.5.

Figure 5.3 Macrozonation map for 500 years return period (Azlan et al,

2006)


Figure 5.4 Result of ground response analysis

Figure 5.5 Time history at surface (0.161g) for Sultan Azlan Shah Bridge

Response spectrum analysis used IBC2000 to construct the design response spectrum. The design response spectrum can be seen in Figure 5.6.


Figure 5.6 Design response spectrum using IBC2000 (modified) SEISMIC ANALYSES TWO DIMENSIONAL ANALYSIS OF AZLAN SHAH BRIDGE The seismic analysis of Sultan Azlan Shah Bridge was carried out using SAP2000 for two-dimensional modelling. Figure 5.7 shows the computer model simulation for Sultan Azlan Shah Bridge. Three types of seismic analyses were implemented in this study; the free vibration, Time History and Response Spectrum analyses respectively.

Figure 5.6 2D modeling by SAP2000


FREE VIBRATION ANALYSIS The free vibration analysis will consider five modes for two- dimensional modeling (Figure 5.8). The periods of structure are shown in Table 5.1. Figure 8 shows the mode shape 1 of the bridge structure.

Figure 5.7 2D modeling by SAP2000

Figure 5.8 Mode shape 1 of bridge structure

Table 5.1 Natural periods of bridge

No 1 2 3 4 5

Period(s) 0.12995 0.08647 0.06065 0.04653 0.04396

TIME HISTORY ANALYSIS Time history analysis of Sultan Azlan Shah Bridge model was performed using two-dimensional models. The time history analysis results with PGA of 0.161g are shown in Figure 5.5.The maximum forces of the structure can be seen in Table 5.2.


Table 5.2 Maximum applied force for 2D time history analysis

Component P(kN) V(kN) BM(kNM)

Deck - 794 12985

Pier 2049 - 987

RESPONSE SPECTRUM ANALYSIS IBC2000 was used to construct the design response spectrum shown in Figure 5.6. The maximum responses for deck and pier can be seen in Table 5.3.

Table 5.3 Maximum applied force for 2D response spectrum analysis


Deck - 852 13728 Pier 2113 - 1465

THREE DIMENSIONAL ANALYSIS OF AZLAN SHAH BRIDGE The seismic analysis of Sultan Azlan Shah Bridge used SAP2000 for its 3 dimensional modeling. The deck and pier of the bridge were modelled using shell and beam elements. There are three types of analysis implemented in this research; the free vibration, time history and response spectrum. Figure 5.9 and 5.10 shows the elevation and side view of bridge modeling.


Figure 5.9 The elevation of three dimensional modeling

Figure 5.10 Side view of three dimensional modeling FREE VIBRATION ANALYSIS The free vibration analysis considered five modes. The periods of structure are shown in Table 5.4. Figure 5.11 shows the mode shape 1.

Figure 5.11 Mode shapes 1

Table 5.4 Five natural periods of bridge

No 1 2 3 4 5

Period(s) 0.19148 0.17500 0.15701 0.14494 0.12181


TIME HISTORY ANALYSIS Time history analysis of Sultan Azlan Shah Bridge model was performed using three-dimensional models with time history of PGA = 0.161g (Figure 5.5). Maximum response of structures can be seen in Table 5.6.

Figure 5.12 Maximum displacement is 0.051m

Table 5.6 Maximum applied force for 3 dimensional time history analysis


Deck 835 616 10390 Pier 749 1615 20225

RESPONSE SPECTRUM ANALYSIS The applied design acceleration response spectrum is shown in Figure 5.6. The result of analysis is presented in Table 5.7. Figure 5.13 shows the displacement value at the bridge deck.


Table 5.7 Maximum applied force of bridge for 3 dimensional response spectrum analyses


Deck 1731 1478 23409 Pier 1665 3431 60106

Figure 5.13 Maximum displacement is 0.056m

NONLINEAR SEISMIC DAMAGE INELASTIC ANALYSES The seismic analysis of Sultan Azlan Shah Bridge in Perak was carried out using IDARC for 2 dimensional modeling. From the analysis, the bridge started to crack at 0.25g and collapsed at 0.32g. The sequence of segment cracking or yielding can be seen at Figure 5.14 to 5.18. Figure 5.18 presents the location of the first beam yield at T = 4.505 second.


Figure 5.14 Flexural crack initiated at first span at PGA = 0.25g

Figure 5.15 The flexural crack initiated at the first span and bottom of all

piers at PGA = 0.27g

Figure 5.16 Flexural crack initiated at first, third and fourth span and

bottom of all piers at PGA = 0.29g

Figure 5.17 Flexural crack initiated at first, second, third and fourth span

and bottom of all piers at PGA = 0.31g


= Initial Cracking = Plastic Hinge Develop = Local Failure

Figure 5.18 Location of first beam and column yielding at PGA = 0.32g CAPACITY OF STRUCTURES To be able to know whether Sultan Azlan Shah Bridge could resist the force from external load, the response should not be not more than the structural capacity of the bridge. In this study the structure capacity was divided into 2 parts; deck and pier section. For the deck capacity, the forces considered were bending moment and shear stress capacity. While for the pier, the forces considered were bending moments and axial forces. It should be noted that due to lack of field strength testing of the concrete, increase in concrete strength due to aging was not considered and on the other hand, no strength reduction factors were applied for capacity calculations. The column moment and axial force interaction diagram can be seen in Figure 5.19. By using strain compatibility method, we found that the bending moment resistance of prestressed concrete boxgirder of Sultan Azlan Shah Bridge was 24854 kNM and the ultimate shear force is 5730 kN.


Figure 5.19 P-M interaction diagram

CONCLUSION Based on the comparison between the maximum response and the capacity of Sultan Azlan Shah Bridge in Perak, it can be seen from Table 5.8 that all the responses for deck have not reached the capacity of the bridge, however, the response of the column for three dimensional response spectrum analyses more than capacity.

Table 5.8 The comparison of maximum applied and capacity force for bridge deck

TH-2D RS-2D TH-3D RS-3D Capacity

Max Shear (kN) 794 852 616 1478 5730 DECK

Max BM (kNM) 12985 13728 10390 23409 24854


Table 5.9 The comparison of maximum applied and capacity force for the bridge pier

TH-2D RS-2D TH-3D RS-3D CAPACITY

Max Axial (kN) 2049 2113 749 1665 Refer to PIER

Max BM (kNM) 987 1465 20225 60106 Figure 19

From the analysis, it can be concluded that the column of Sultan Azlan Shah Bridge is under the assigned earthquake loadings but the column response for three dimensional response spectrum analyses is higher than the capacity when subjected to local site effect of PSA = 0.161g. The bridge started to initiate cracks at 0.25 g and collapsed at 0.32g. REFERENCES Chopra,A.K.1995. Dynamics of Structures: Theory and

Application to Earthquake Engineering. New Jersey, Prentice Hall , Inc

Adnan,A.1998. Low Intensity Earthquake Effects on Steel Girder Bridges. PhD Theses, Universiti Technology Malaysia.

Yazdani-Motlagh A.2002.Inelastic Seismic Behaviour of Stiffening Systems Multi Span Simply Supported (MSSS) Bridges. PhD Theses, New Jersey Institute of Technology.

Adnan,A. Taib, I.M & Suhatril,M. 2008. Seismic performance of sungai merang bridge in Terengganu under low earthquake ground motion. Proceeding of International conference on earthquake engineering and disaster mitigation, Jakarta

Hendriyawan. 2007. Macrozonaton of Peninsular Malaysia and microzonation of Kuala Lumpur and Putrajaya. PhD theses. Universiti Teknologi Ma

advanced in earthquake engineering applications

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