近年来,越来越多的高层建筑采用了基础隔震技术,但研究表明,高层隔震建筑在超烈度地震作用下仍可能发生破坏或倒塌,因此开展高层建筑隔震前后的地震风险对比分析显得尤为重要,可直观显示该类建筑在将来可能发生地震作用下的表现。在进行隔震结构地震风险分析时,上部结构、隔震支座、地震动的不确定性对易损性分析结果有重要影响,因此本文以高层RC框架剪力墙结构为研究对象,在综合考虑隔震支座、上部结构和地震动参数随机性的基础上,定义上部结构层间位移角及隔震层位移2个参数为结构损伤的评价指标,对隔震前后结构的地震易损性进行了对比分析,进而开展地震风险评价。结果表明:隔震技术极大地减小了结构的地震脆弱性,提高了结构的抗震安全性,但其在超烈度大震作用下也具有倒塌的风险;相比于非隔震结构,隔震结构的风险损失值可降低6倍。
In recent years, more and more high-rise buildings use the base isolation technology, but the research indicates that high-rise isolated buildings also may be seriously damaged and collapsed, so it should be paid more attention to compare the seismic risk loss of high-rise buildings with or without the isolated layer, which can obvi- ously show the seismic performance of the isolated building under earthquakes that may occur in the future. During the course of seismic risk analysis of isolated buildings, the uncertainty of upper structure, isolators and ground mo- tion will greatly influence the vulnerability analysis result. In the paper, a high-rise RC frame-shear building is taken as the study subject, after considering the randomness of upper structure, isolated rubber bearing and ground motion, the displacement of the isolated layer and the story drift ratio of the upper structure are selected as the dam- age evaluation indexes. The comparative analysis of seismic vulnerability for high-rise buildings with or without the isolated layer is done, and then the seismic risk assessment is made. It can be seen that: the isolation technology can apparently decrease the seismic risk and increase the seismic safety, but the isolated building still may collapse under very rarely occurred earthquake; the seismic risk loss of the building without the isolated layer is 6 timesgreater than that of the isolated building.