古建筑隔震动力时程分析

Dynamic time history on seismic isolation of ancient building

利用数值模拟方法研究采用隔震技术保护古建筑抗震安全性.建立了非隔震和隔震东宫门古建筑2种三维实体有限元模型,进行模态分析和动力时程分析.通过输入不同频谱的天津波、EI Centro波和人工波,对比分析了2种模型结构动力特性及在罕遇地震作用下的位移、加速度时程曲线.结果表明:非隔震与隔震东宫门各阶模态基本一致,但隔震结构基本周期明显增大,有效地减小了地震作用.在天津波、EI Centro波和人工波作用下,隔震结构比非隔震结构位移和加速度分别减少了33.29%、63.74%、55.67%和91.04%、91.67%、91.43%,隔震支座极大地减少地震反应.本文的隔震研究可为类似古建筑的抗震保护提供一定的参考.

The seismic safety of ancient building using seismic isolation technology is investigated by numerical simulation method. Two three-dimensional finite element models of non-seismic isolation and seismic isolation of Donggongmen were conducted, the modal analysis and the dynamic time history analysis were proceeded.The structural dynamic characteristics and the displacement, acceleration time history curves of the two models were compared and analyzed by inputting different frequency spectrum of Tianjin wave, EI Centro wave and artificial wave under infrequent seismic actions. The results show that non-seismic isolation structure and seismic isolation structure are the same in forms of vibration, but isolation structure of the basic period is obviously increased, which effectively reduces the seismic effect. Under the action of Tianjin wave, Centro EI wave and artificial wave, the displacement of the isolated structure are respectively reduced by33.29%, 63.74%, 55.67%; and the acceleration of the isolated structure are respectively reduced by 91.04%, 91.67%,91.43%. Seismic isolation bearings greatly reduce seismic response. The study of seismic isolation in this paper can provide a reference for the seismic protection of other similar ancient building.