The present study is intended as analysis investigations of fatigue durability of the trough to deck plate welded joint failed at weld root in deck plate. The investigations are carried out on the basis of three key factors: fatigue strengths of the welded details obtained by analysis method in conjunction with fatigue tests, stress ranges by FEM analyses with a unit wheel load, and the loads and their frequencies for the fatigue evaluations are the wheel loads in service, represented by an equivalent wheel load, assumed from the axle load measurements. Consistency between fatigue strength and stress range is simply demonstrated. Using this method for fatigue evaluation, it is found that large-rib-deck model has longer fatigue life than standard-deck models. An increase in deck plate thickness may prolong fatigue life of the orthotropic steel deck. Load distribution due to the rigidity of pavement may also help enhancement the fatigue life.

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This study describes an analytical proposal to predict lateral shear capacity of confined masonry walls that fail by diagonal splitting, where the maximum shear is evaluated as the dowel action of confined columns' reinforcement added to the shear capacity of the plain masonry panel. In order to validate the proposed approach, experimental test results and gathered data from literature were used. The experimental tests concerned two confined clay brick walls subjected to different level of gravity load and cyclic lateral loading. The applicability of some empirical formulae found in literature regarding the stiffness degradation was investigated. Good correlation between the predicted lateral resistance using the proposed approach and all data was achieved.

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Presented in this paper is shaking table tests of a bridge isolated by four different sliding bearings in order to investigate the seismic response with emphasis on frictional characteristics of the sliding bearings with different sliding materials, the effect of vertical, transverse excitation and the frictional coefficient difference on seismic responses, and the generation mechanism of vertical force variation at the sliding bearings. The test results showed that combinations of vertical and horizontal excitations as well as longitudinal and transverse excitations generated larger responses compared with merely longitudinal excitation in case of a sliding bearing with high frictional coefficient and large velocity dependence, and that the effect of the four different frictional coefficients on the maximum and residual displacement became clear. Furthermore, it was found that shear keys at rubber buffers might affect vertical force variation at the sliding bearing.

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Considering the seismic risks associated with structural damage and loss caused by various seismic forces, the total cost cannot necessarily be minimized by the verification of seismic performance using two levels of seismic forces (Levels 1 and 2 earthquake motion). Here, the total cost is defined as the summation of the initial construction cost and the seismic risk cost, which includes repair and user costs. The seismic force, with which the total cost becomes the minimum, is thought to vary with the function and type of the structure to be designed. From such a point of view, this paper presents a method for determining the target seismic design force unique to the intended structure.

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In this study, the mechanisms associated with the seismic response of a long-period structure when subjected to a long-period seismic excitation are clarified. A typical scale cable-stayed bridge with prestressed concrete girders (PC cable-stayed bridge) was selected for analysis. First, we simulated long-period components of the ground motion at the site of the Ji-Lu Bridge, which was damaged in the 1999 Chi-Chi, Taiwan earthquake, and the damage of the bridge was assessed by nonlinear seismic analysis using the simulated ground excitations. Second, shaking table tests of a model PC cable-stayed bridge were carried out, in consideration of the similarity law, to clarify the mechanisms involved, focusing on the linear and nonlinear seismic responses of the tower and cables.

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