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CONTENTS
Volume 20, Number 1, May10 2005
 

Abstract
The present paper deals with the seismic response analysis and the evaluation of most likely failure modes for a water storage structure. For the stress analysis, a 3-D mathematical model has been adopted to represent the structure appropriately. The structure has been analyzed for both static and seismic loads. Seismic analysis has been carried out considering the hydrodynamic effects of the contained water. Based on the stress analyses results, the most likely failure modes viz. tensile cracking and compressive crushing of concrete for the various structural elements; caused by the seismic event have been investigated. Further an attempt has also been made to quantify the initial leakage rate and average emptying time for the structure during seismic event after evaluating the various crack parameters viz. crack-width and crack-spacing at the locations of interest. The results are presented with reference to peak ground acceleration (PGA) of the seismic event. It has been observed that, an increase in PGA would result in significant increase in stresses and crack width in the various structural members. Significant increase in initial leakage rate and decrease in average emptying time for the structure has also been observed with the increase in PGA.

Key Words
tension/compression zone; cracking; crushing; crack-width; crack-spacing; seismic; tank; water; failure.

Address
Kapilesh Bhargava; Engineering Services Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
A. K. Ghosh; Health Safety and Environment Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
S. Ramanujam; Engineering Services Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India

Abstract
Masonry is a composite non-homogeneous structural material, whose mechanical properties depend on the properties of and the interaction between the composite components - brick and mortar, their volume ratio, the properties of their bond, and any cracking in the masonry. The mechanical properties of masonry depend on the orientation of the bed joints and the stress state of the joints, and so the values of the shear modulus, as well as the stiffness of masonry structural elements can depend on various factors. An extensive testing programme in several countries addresses the problem of measurement of the stiffness properties of masonry. These testing programs have provided sufficient data to permit a review of the influence of different testing techniques (mono and bi-axial tests), the variations caused by distinct loading conditions (monotonic and cyclic), the impact of the mortar type, as well as influence of the reinforcement. This review considers the impact of the measurement devices used for determining the shear modulus and stiffness of walls on the results. The results clearly indicate a need to re-assess the values stated in almost all national codes for the shear modulus of the masonry, especially for masonry made with lime mortar, where strong anisotropic behaviour is in the stiffness properties.

Key Words
masonry; shear modulus; stiffness; experimental; compressive test; diagonal test; shear test; static and dynamic loading.

Address
Vlatko Z. Bosiljkov; Slovenian National Building and Civil Engineering Institute (ZAG), Section for Earthquake Engineering, Dimieva 12, Ljubljana, SI-1000, Slovenia
Yuri Z. Totoev; Faculty of Engineering and Built Environment, University Drive, Callaghan, NSW 2308, Australia
John M. Nichols; Department of Construction Science, College of Architecture, Texas A&M University, College Station, TX 77823-3137, USA

Abstract
This paper presents a new approach to predict the racking load-displacement response of plasterboard clad walls found in Australian light-framed residential structures under monotonic racking load. The method is based on a closed-form mathematical model, described herein as the

Key Words
light-framed structures; plasterboard; gypsum; timber construction; shear resistance; bracing; mathematical modelling.

Address
Y. L. Liew; Department of Civil and Environmental Engineering, The University of Melbourne, Victoria 3010, Australia
E. F. Gad; School of Engineering and Science, Swinburne University of Technology, P.O. Box 218, Hawthorn, Victoria 3122, Australia
C. F. Duffield; Department of Civil and Environmental Engineering, The Australian Centre for Public
Infrastructure, Melbourne University Private, Victoria 3052, Australia

Abstract
In many cases, underground structures are built using conventional above-grade structural systems to carry gravity load. This paper proposes the use of underground arches, termed

Key Words
reinforced concrete; arches; creep; shrinkage; underground structures.

Address
Enrique Hernandez-Montes; University of Granada, Campus de Fuentenueva, 18072 Granada, Spain
Mark Aschheim; Civil Engineering Department, Santa Clara University, 500 El Camino Real, Santa Clara, CA 95053, USA
Luisa Maria Gil-Martin; University of Granada, Campus de Fuentenueva, 18072 Granada, Spain

Abstract
This paper aims at formulating various statistical models for the study of a ten year Weigh-in-Motion (WIM) data collected from various WIM stations in Hong Kong. In order to study the bridge live load model it is important to determine the mathematical distributions of different load affecting parameters such as gross vehicle weights, axle weights, axle spacings, average daily number of trucks etc. Each of the above parameters is analyzed by various stochastic processes in order to obtain the mathematical distributions and the Maximum Likelihood Estimation (MLE) method is adopted to calculate the statistical parameters, expected values and standard deviations from the given samples of data. The Kolmogorov-Smirnov (K-S) method of approach is used to check the suitability of the statistical model selected for the particular parameter and the Monte Carlo method is used to simulate the distributions of maximum value stochastic processes of a series of given stochastic processes. Using the statistical analysis approach the maximum value of gross vehicle weight and axle weight in bridge design life has been determined and the distribution functions of these parameters are obtained under both free-flowing traffic and dense traffic status. The maximum value of bending moments and shears for wide range of simple spans are obtained by extrapolation. It has been observed that the obtained maximum values of the gross vehicle weight and axle weight from this study are very close to their legal limitations of Hong Kong which are 42 tonnes for gross weight and 10 tonnes for axle weight.

Key Words
weigh in motion; stochastic process; Monte Carlo method; gross vehicle weight; axle weight; inattentive traffic status; dense traffic status.

Address
Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong

Abstract
The dynamic interaction of vehicle-bridge is studied by using transfer matrix method in this paper. The vehicle model is simplified as a spring-damping-mass system. By adopting the idea of Newmark-b method, the partial differential equation of structure vibration is transformed into a differential equation irrelevant to time. Then, this differential equation is solved by transfer matrix method. The prospective application of this method in real engineering is finally demonstrated by several examples.

Key Words
dynamic interaction of vehicle-bridge; transfer matrix method; Newmark-b method; Euler-Bernoulli beam.

Address
Department of Bridge and Structural Engineering, Southwest Jiaotong University, Chengdu, 610031, P.R. China

Abstract
Design details pertaining to the connection between some recently developed fiber reinforced polymer (FRP) composite deck systems and the supporting girders require openings through cells of the deck. This significantly changes the stress distribution in these components. As a result, the conventional assumptions that deck designs are controlled by their stiffness, and not strength, needs a closer examination. This paper proposes an analytical method to investigate the stress states and failure mechanisms using a type of ?lobal-local?modeling perspective, incorporating classical lamination theory and first ply failure criterion with use of appropriate stress concentration factors around the cutouts. The use of a ?meared-stress?approach is presented as a potential means of simplifying certain FRP specific complexities, while still enabling prediction of overall failure.

Key Words
decks; finite element analysis; cutout; stress concentration; first-ply failure.

Address
Lei Zhao?epartment of Civil and Environmental Engineering, University of Central Florida,Orlando, FL 32816-2450, USA
Vistasp M. Karbhari?epartment of Structural Engineering, University of California San Diego, MC-0085, La Jolla, CA 92093-0085, USA


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