This paper describes an influence of composite effect of concrete slab on both mechanical characteristic and earthquake response of frames. The influence of composite effect was examined by comparing three kinds of analytical methods. As a result, it was observed that the effect of concrete slab had great influence on natural period of the frames, ultimate base shear coefficient, and maximum story drift angle. It was clarified that they could be estimated only by considering increase of flexural stiffness of steel beams.
The purpose of the present study is to develop the elastic-plastic analytical model of screw which demonstrates slipping behavior in steel framed houses. This model consists of multiple yield surfaces and slip slot. The analytical results represent the characteristic behaviors of test which restoring force declines because screws becomes plastic by the influence of load behavior and increases little by little throughout slipping period. As a analytical result, it turned out that the behavior of wall was dependent on screws.
Smart and intelligent buildings with seismic control devices for reducing the earthquake responses and damages were recently practically applied for many projects. The authors have been proposed the new hysteresis damper of the buckling-restrained brace with triple steel tubes, and its excellent mechanical characteristics under the both tension and compression loading had been confirmed in our previous papers by the full-scale tests. This paper shows the results of full-scale cyclic tests, and confirmed the scope of application on this damper with slit holes.
This paper presents a proportioning method for members of single layer cylindrical latticed roofs considering shell-like buckling. The present method is applicable for proportioning members of not only roofs of short span but also roofs of long span, because the method defines both the elasto-plastic buckling strength of longitudinal members and that of diagonal members, respectively. This paper discusses also the effectiveness of the proportioning method by comparing the load carrying capacity of roofs designed using the presented proportioning method with the load for design.
In Japan high seismic performance is demanded to the school buildings, because they must accommodate students and regional peoples in safe during and after the severe earthquakes. However, many of these gymnasiums built before 1981 do not meet the present Japanese national seismic regulations. A seismic diagnosis and upgrading of these gymnasiums have been carried out in Japan. In this study, seismic performance of the school gymnasiums in the Cyugoku district are introduced from the database built on the basis of 323 seismic diagnosis reports. Seismic damages of these gymnasiums according to 2000 Tottoriken-Seibu earthquake and 2001 Geiyo earthquake are introduced.
Energy absorbing connecters consisting of shoes and steel bellows have been investigated by the authors as one of economical seismic design methods for a system of new steel bridge girders supported by piers. The shoes are designed to collapse as fuse members intentionally in this method in order to decrease inertia forces caused by a strong earthquake. The inertia forces and response displacement of the girders after the collapse of the shoes are restrained for the effect of energy absorption due to plastic deformations of the steel bellows. In this paperinvestiga ted is the method in which the connecters are applied to the seismic design of existing steel bridge girders. Firstly, a numerical simulation method is explained to estimate the seismic behavior of a bridge system. Secondly, the necessary conditions are discussed to apply the connecters to existing steel girder bridges. Thirdly, a trial design is carried out to investigate the seismic retrofitting method of medium-span girder bridges using the connecters. Validity of the connecters is finally confirmed by the nonlinear seismic response analysis using results of the trial design.
Tapered steel plates are classified into 2 categories by the difference of directions of applied force and thickness change; Longitudinally profiled steel plates and transversely profiled steel plates. It is confirmed that the former can be applied to steel bridges and make it possible to reduce the construction cost and improve sstmctutal rationality. The latter is also studied and it is shown that it is also effective for improving strength and ductility in case of the square plate by parametric numerical approach Proposed herein is the evaluation of ultimate strength of both tapered steel plates considering various boundary conditions, longitudinally and transversely profiled steel plate and its validity has been discussed.