水平二方向および上下方向地震動入力を受けるRC造立体架構の弾塑性地震応答解析

Abstract

In order to have more general and proper understanding to the plastic behaviors of space structures under strong earthquake excitations, the effects of vertical ground motion also should be taken into considerations.According to the past reports on earthquake damage, some of the damages of structures caused by the vertical component of near field earthquake were observed. However, few researches dealing with the earthquake response of structures subjected to multi-components of ground excitations have been carried out.In this paper, to investigate the effects of vertical motion, mass points are supposed to be concentrated on the top part of column members and central part of beam members. Interactions of bi-axial bending moments and axial force in the nonlinear joints of column members are considered by the introduction of plastic theory. By using this method, authors analyzed a series of 3-story reinforced concrete(RC) space frames of different span length and yeilding mechanism and a 8-story RC space frame under multi-components of recorded earthquake waves.The response results show that the effects of vertical ground motions are quite different for the low-rise structures and relatively high-rise structures, that is, to the relatively high-rise weak-beam structure, those effects are remarkable both in the structural member level and story level.