The structural performances of composite tubular K-joint leading to real truss bridge construction of high speed Shinkansen train are presented. The experimental studies on improving the fatigue performance of welded steel tubular joints by upgrading the structural joint details and improving the weld toe profiles were carried out on ten tubular K-joints under repeated constant amplitude load. The behaviour of all joints were examined through the analyses and the tests. The results suggest that concrete filled tubular joints are able to improve the fatigue strength substantially compared to unfilled joint.

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Seismic hazard and microzoning of the Philippines are presented. Seismic hazard analysis of the Philippines on rock-surface level is done to all land areas of the country. The analysis includes both the historical earthquake occurrences and active fault data. Ground motion amplification corrections based on surface geology is determined based on the representative soil softness index of each geology type. The resulting amplification corrections are applied to the rock-surface seismic hazard of the Philippines. A significant increase of seismic hazard by applying the amplification corrections is shown for the city of Manila.

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The following factors are identified to have a critical effect on seismic risk in Greece. First, exposure to seismic hazard is strongly non-uniform, with over half of the country’s 10 million population- and accordingly most of the industry and infrastructure-concentrated in only two major urban conglomerates. In addition, many of the potentially damaging earthquakes occur in sparsely populated areas or have their foci under the sea. Last, the enforcement and upgrading of seismic codes since 1959, in combination with a generally good quality of construction materials and workmanship, contribute to a relatively reduced vulnerability of structures.

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The effective length concept has been widely accepted in the design of framed structures. An excessive accuracy is not to be expected from its origin apart from structural analysis, but there still remain certain cases where its estimation is far conservative beyond reality. The practice for a rectangular frame is set up differently depending upon whether braced or unbraced. Literally, the effective length has been designated as an axial strength of individual members. In this study, an inadequacy is found in those conventional practices, and an alternative manner is suggested to deal with the structural buckling of a rectangular frame.

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In this study a 3D nonlinear parallel FEM formulation was derived for dynamic soil structure interaction problems. To express the nonlinear property of the saturated soil the simplified bounding surface model was used referring the Wolf and Crouch’s study. In the implementation of the parallel processing algorithm for the 3D nonlinear FEM formulation, Domain Decomposition Method and Conjugate Gradient Method were applied. To see the validity of the proposed parallel analysis a seismic earth pressure test using a shaking table was simulated. The numerical results for the seismic active earth pressures and dynamic pore water pressures acting on the wall coincide well with those of the experiment.

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A seismic risk assessment procedure based on the fragility curve concept is proposed in this paper. First, damage criteria for gravity type quay walls in terms of normalized seaward displacement are proposed considering the restoration cost. Second, a procedure to generate the fragility curve for each damage level using Monte Carlo simulation is proposed. Third, the fragility curves are utilized for the risk assessment of a quay wall under certain conditions based on the result of seismic hazard analysis. Finally, the proposed risk assessment procedure is examined with a case history from the 2000 Tottori-ken seibu earthquake.

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Geologic observations have indicated that moderate- to large-scale faults have moved repeatedly in the recent geologic past. This allows us to evaluate the future behavior of a fault based on geologic information. In this paper, the essential characteristics of active faults are reviewed, and problems in evaluating surface faulting by using geologic information are discussed.

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The 1999 Kocaeli and Düzce earthquakes of Turkey caused loss of many people and severe structural damage to structures. In addition to poor quality construction and inappropriate construction materials, the damage was caused partly by the permanent displacement of the ground due to faulting and partly by the liquefaction and lateral spread of the ground. The aim of this paper is to make an attempt to describe the general features of the surface ruptures and related ground failures and damage to structures, and to discuss several important examples from both earthquakes which may be precursory for the earthquake engineering community to develop seismic codes for structures in active fault zones.

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Earthquakes in different geological regions show drastic variations in their effects such as, large surface upliftment/displacements of unconsolidated soil deposits. For this reason, we attempted to develop a new application of Applied Element Method (AEM) to study the ground surface deformation near fault rupture zone. First, preliminary analysis is carried out to check the applicability of the method. Results are compared with the results from analytical and experimental methods and they showed good agreement. Non-linear modeling is carried out to study the effects of dip-slip faults on the ground surface. Detailed study is carried out using two cases of dip angles in both normal and reverse dip-slip fault conditions.

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This paper describes the damage of bridges resulting from the fault movements in the 1999 Kocaeli and Duzce, Turkey, Earthquakes and the 1999 Chi-Chi, Taiwan, Earthquake. Effect of the fault displacement on the seismic performance of bridges is presented with an emphasis on the mechanism of failure.

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The instrumented period for earthquakes is relatively short to understand their mechanism and characteristics in many countries. Even at present time, there are many areas in the world where seismic instruments are still insufficient. Therefore, it is very difficult to know the mechanism and the characteristics of future earthquakes in any place because of either the lack of instrumentation and/or the shortness of the instrumented period. In this article, the authors present a methodology for inferring the possible mechanism and characteristics of earthquakes from the ground surface traces and striations of existing faults. The methodology is then applied to the faults of certain locations in Turkey and compared with actual observations in order to see its validity and applicability.

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We performed sandbox tests and numerical analysis of the tests to investigated the deformation of the sand by reverse faulting. Test results can be simulated generally well by FEM using elasto-plastic solid elements and joint elements, if the stress-strain relation of the sand is adequately modeled. We applied our numerical model to prototypic real scale sandy alluvium model. The analyses of 30m, 50m and 75m deep alluvium suggested that the failure surface propagates through the alluvium if the vertical bedrock fault displacement reaches 3-7% of the depth of the alluvium. It is unlikely that the shear failure propagates through 100m deep alluvium.

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The Shiwei Bridge in Taiwan was extensively investigated in order to determine the reasons for its failure during the 1999 Chi-Chi Earthquake. Our field investigation revealed no evidence of horizontal displacement in any of the bridge’s piers, although the foundations of the piers were rotated. Two possible scenarios for the failure of the girders are proposed: 1) when the foundations rotated, the distance between the piers became greater than the length of the girder, causing the girders to fall; or 2) the direction of the seismic motion was perpendicular to the axis of the bridge, causing the girders to rotate and fall.

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This paper presents the models experiment and the numerical simulations of a surface earthquake fault which is induced by the lateral strike slip of the bedrock mass. These studies are made to observe and reproduce the evolution of the fault within soft layers. In the model experiments, the successive bifurcation processes are observed, and they lead to large variability of the faults. The numerical simulation uses a stochastic finite element method which estimates the variability of the fault behavior. Such a stochastic analysis method is a promising tool, since it is able to account for the bifurcation processes and the variability.

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