框架抽柱托换改造抗震性能有限元分析

Finite Element Study of the Seismic Behaviors for Demolishing Column Underpinning Reformation Frames

文章介绍了混凝土框架结构抽柱托换改造后的抗震性能有限元分析研究,分析模型为3个5层两跨平面框架。分为未抽柱框架模型YKJ;预应力转换梁抽柱托换模型YYLKJ;桁架抽柱托换模型HJKJ。通过对三榀框架结构采用SAP2000建模,然后进行Pushover分析,分别得到结构的破坏模式、基底剪力-位移曲线、抗震性能等结果。分析结果表明:在水平地震作用下,3榀框架模型塑性铰开始出现的部位都是梁端,具有较好的变形能力,属于延性破坏,符合强柱弱梁的要求。罕遇地震作用下,YYLKJ和HJKJ两种框架具有较好的安全性,满足"小震不坏,大震不倒"的抗震要求。

This paper presents the finite element study of the seismic behaviors on demolishing column underpinning reformation concrete frame structures. Three models of two-dimensional, five-storey and two-span frames are analyzed: the model without demolishing column named YKJ, the model of demolishing column underpinned by prestressed beam named YYLKJ and the model of demolishing column underpinned by truss named HJKJ. By using SAP2000 software, Results of failure modes, base shear-top displacement curves and seismic performance are concluded from pushover analysis on the three frame models. The results show that all three models' plastic hinges appeared firstly at the end of beams and that all three models demonstrate considerable deformation capacity and ductility failure so it obeys the principle of strong column and weak beam. YYLKJ and HJKJ models have enough safety performance to satisfy the seismic requirements of ' no damage under frequent earthquake and no collapse under severe earthquake'.