软土场地基础隔震建筑减震性能研究

本文研究土与结构相互作用(SSI)对多层及中高层基础隔震建筑地震需求及隔震效率的影响规律,隔震层采用LRB铅芯橡胶与LNR普通橡胶隔震支座组合,就我国现行《建筑抗震设计规范》(GB50011-2010)中软土场地设置隔震层问题做探讨。提出土与基础隔震结构相互作用的简化计算模型,对不同场地及隔震设计目标下的多层及中高层基础隔震结构进行时程分析。研究表明:软土场地基础隔震建筑隔震层的有效隔震效率相对于硬土场地有所下降,必须通过设置具有一定规格的LRB支座来满足隔震目标。本文给出了铅芯橡胶支座极限变形需求随建筑层高及隔震目标变化的规律。

Seismic response reduction of base-isolated buildings located on soft soil sites

This paper studies the influence of soil-structure interaction(SSI)on seismic demands and isolation efficiency of multi-storied,low and medium-rise base-isolated buildings with lead-rubber bearings(LRB)and ordinary-rubber bearings(LNR).The issues related to the base isolation on soft soil sites in the Chinese Code for seismic design of buildings are discussed.A simplified SSI model was proposed for base-isolated structures with time history analyses being performed on low and medium-rise base-isolated buildings on different sites designed for prescribed isolation targets.The results show that,despite the fact that the effective isolation efficiency of the isolation layer decreases for buildings on soft soil sites than on hard soil sites,the isolation layer must be set with the dimensions of the LRB isolators chosen carefully.The relationship between the peak deformation demands of LRB isolators and number of stories for different levels of isolation targets are provided.