基于子结构频率匹配机制的城市综合体高层结构分层隔震性能研究

Study on Seismic Performance of Urban Complex High Rise Building with Layered Isolation System based on Substructure Frequency Matching Mechanism

为实现城市综合体高层结构"可恢复功能"防震目标,建立了综合体高层结构分层隔震体系,以应对裙房-塔楼结合部刚度突变对整体结构动力特性的不利影响,缓解(超)高层塔楼因高宽比过大导致隔震应用受限的问题。基于振型参数分析假定裙房部分侧移形状函数,在此基础上建立整体系统简化动力学模型,通过求解频率响应传递函数,建立子结构间频率匹配关系,调整各子结构频率以优化整体结构动力特性,开展有限元分析验证综合体高层结构分层隔震机制。结果表明:与抗震及单层隔震相比,双层隔震能更有效地控制结构地震响应,基于子结构间频率匹配关系可优化结构整体地震动特性,因此,分层隔震体系是一种适用于复杂、高耸结构的有效防震手段。

For the purpose of achieving the goal of"resilience"of urban complex high-rise building,a layered isolation system for high-rise complex structure is proposed,which can avoid the adverse effect of sudden stiffness variation of podium-tower junction on the dynamic response of the whole structure,and alleviate the problem of limitation of using isolation in(super)high-rise tower due to large height-width ratio.Based on the analysis of modal parametric study,the lateral displacement shape function of the podium is determined,and a simplified dynamic model is established.By optimizing the frequency of each substructure,the seismic performance of the whole structure is improved.Finite element analysis is carried out to verify the principle of double layered isolation of high-rise complex.The results show that,comparing with the aseismic structure and single-layer isolation,double-layer isolation can more effectively control the seismic response of the structure,and the dynamic characteristics of the whole structure can be optimized by adjusting the frequency to match that of substructures.Therefore,the layered isolation system is a high-efficiency earthquake prevention method for complex and high-rise structures.