Study on Structures and Equipments Supported on Seismic Isolator

近年来，隔震体系的研究及其实现的发展十分活跃。本研究的目的在于通过为建筑物或机器提供非常软的弹簧，在不同类型的抗震体系中寻找可行的、可用的和足够的支承体系，以降低地震威力。消能工采用粘滞型、摩擦型和滞回型。对实心和软弱地基的输入地震响应进行了模拟计算。并对叠层橡胶和消能器进行了精确的参数研究。此外，对非隔震建筑和隔震建筑的地震反应进行了比较，说明隔震装置可以降低进入建筑物上部的地震动力。隔震效果越好，地震功率水平越高。从控制地震后残留的大反应位移的角度出发，如何选择消能器的类型是非常重要的，隔震建筑的楼层反应谱表明，建筑中的二次结构和设备可以不受强烈激励。与非隔震结构相比，加速反应谱没有明显的优势频率。特别是在摩擦耗能器的情况下，没有出现窄带峰值，叠层橡胶支座的隔震器可能会引起摇摆振动。对摇摆振动也进行了分析。给出了定量的结果。

Recently, Researches for seismic isolation systems and the development of the realization of them have been highly activated. The objective of this study lays in searching for the feasible, available and adequate supporting system among various seismic systems limited to the type that can reduce the seismic power by means of providing buildings or machines with very soft springs.Dynamic chraracteristics of multi-storied RC buildings provided with seismic isolation systems, which consists of laminated rubber bearings and some kind of dissipators, are discussed. Viscous, frictional and hysteretic types are adopted as dissipators. Simulations of response to input earthquakes which corresponds to the solid and soft ground have been carried out. The precise parameter study of laminated rubbers and dissipators has been also carried out. Furthermore seismic response of non isolated building is compared with isolated one.Suffice to say that the seismic isolater can reduces the seismic power into the upper part of buildings. The more effective the seismic isolator become, the higher earthquake power level is. From the point of controlling large response displacement which remains after earthquake, it is important how to select the type of dissipators.Response spectra of the floor response obtained in the isolated building reveal that secondary structures and equipments in the building may be made free from severe excitations. Accelaration response spectra, compared with that of the non isolated building, has no distinct predominant frequencys. Especially in the case of frictional dissipators, no narrow band peak appears.Rocking vibrations may be induced by the seismic isolator using laminated rubber bearings. Analysis of rocking vibrations has been also carried out. Quantitative results are obtained.