隔震支座楼梯框架结构的Pushover分析

Pushover Analysis of the Seismic Isolation Bearing Stair Frame Structure

摘要: 采用SAP2000软件，分别建立了不设置楼梯，设置普通楼梯，以及在楼梯梯板下端设置隔震支座的3种不同形式钢筋混凝土框架结构的有限元分析模型，通过模态分析研究了不同楼梯形式对钢筋混凝土框架结构周期和振型顺序的影响。通过静力推覆分析(Pushover分析)，研究了地震作用下普通楼梯和隔震支座楼梯两种模型的抗震性能及屈服机制。研究表明：设置楼梯可以改变框架结构的振型顺序，在梯段板下方设置隔震支座后，楼梯的塑性铰发展变得更为缓慢，楼梯抗震性能得到了明显改善。

Abstract: Employing SAP2000 software, finite element analysis models were developed for three distinct types of reinforced concrete frame structures: without staircases, with conventional staircases, and with seismic isolation bearings installed at the bottom of stair flights. Modal analysis was conducted to investigate the influence of different staircase configurations on the natural periods and mode shape sequences of the reinforced concrete frames. Through static pushover analysis (Pushover analysis), the seismic performance and yield mechanisms of both conventional staircases and those equipped with isolation bearings were examined under seismic actions. The findings indicate that the presence of staircases alters the mode shape sequence of the frame structure. After installing isolation bearings beneath the stair flights, the development of plastic hinges in the staircase is notably delayed, resulting in a significant improvement in its seismic performance.