不对称大底板多塔楼隔震结构的地震响应分析

针对不对称大底板多塔楼隔震结构体系,通过建立地震响应的动力分析简化模型,推导出不对称大底板多塔楼隔震结构体系地震作用下的运动方程。对一实际的不对称大底板多塔楼隔震结构进行地震响应仿真分析,探讨塔楼质量偏心率和塔楼质量比对结构周期比、位移比和层剪力比的影响。结果显示,不对称大底板多塔楼隔震结构扭转角主要由隔震层产生;与不隔震结构相比,不对称大底板多塔楼隔震体系的扭转角减小,可取得较好的减震效果;塔楼与底板的位置分布和质量分布会影响体系的扭转效应和减震效果,应尽量使塔楼的质心与底板质心重合,塔楼质量分布均匀,以减小结构的扭转效应,提高减震效果。

Seismic Performance of Base Isolated Asymmetric Multi-Tower Structure With Large Floor

The special-type isolated building defined as asymmetric multi-tower structure with large floor is discussed in this paper.The equation of motion for this structure is derived based on the building seismic analysis model.A real multi-tower isolated building with large floor is chose as an example to show the seismic performance of this type of structure.The influences of mass eccentricity and mass ratio on the period ratio,drift ratio and shear force coefficient of the structure are discussed.The following conclusions are obtained:(1)torsional drift obviously depends on the isolated layer in the asymmetric multi-tower with large floor;(2)comparing with the fixed base structures,this special type isolated building can sharply reduce the torsional response;and(3)the effect of isolation reduce with the increase of mass eccentricity of the tower.It is concluded from the study that the multi-tower base isolated building with large floor should be symmetric and concentric for reducing structural seismic response.