基于Benchmark模型的低刚度隔震支座地震响应研究

Study on the seismic response of low stiffness isolation devices based on Benchmark model

建筑隔震设计中广泛使用的铅芯橡胶隔震支座(LRB)在近断层地震作用下,支座位移过大,在满足竖向承载力的同时难以兼顾支座的水平刚度和阻尼值,导致隔震体系的隔震效果不佳,甚至隔震支座可能发生损坏。针对这一问题,研发了一种新型的水平低刚度隔震支座,该支座在满足竖向承载力要求的同时,能将隔震层的水平刚度维持在较低的水准,同时保持较好阻尼性能。本文采用ETABS模拟隔震支座并建立隔震Benchmark模型,通过动力时程分析,对比了传统橡胶隔震方案和水平低刚度隔震方案中结构的最大层间剪力、最大层间位移角和能量耗散等结构响应。结果表明,近断层地震作用下,水平低刚度隔震方案比传统橡胶隔震方案的隔震效果更佳。

Under the near-fault earthquake,the horizontal displacement of the lead rubber bearings in the isolation design is too large.In order to meet the vertical bearing capacity,it is difficult to balance the horizontal stiffness and damping ratio of the bearing,which results in poor isolation performance of the isolation system and even damage to the isolation bearing. In response to this problem,a new type of horizontal low-stiffness isolation bearings is developed. While meeting the requirements of vertical bearing capacity,the horizontal stiffness of the isolation layer is low and the damping performance is good. The isolation bearings and the isolated Benchmark model are established by ETABS software. The maximum story shear force,the maximum story drifts and energy dissipation capacity are selected as evaluation indicators in the analysis. The results show that the isolation effect of horizontal low-stiffness bearing is better than traditional rubber isolation.