基于IDA的带耗能腋撑转换框架地震易损性分析

IDA-Based Seismic Fragility Analysis of Transfer Frame with Energy Dissipation Haunch Braces

基于普通和带耗能腋撑钢筋混凝土转换框架结构的增量动力分析,对两者开展地震易损性研究,并建立其易损性曲线方程,评估带耗能腋撑钢筋混凝土转换框架结构的抗震可靠性,分析防屈曲耗能腋撑对钢筋混凝土转换框架结构破坏机制的影响.研究表明,防屈曲耗能腋撑可显著地降低钢筋混凝土转换框架结构处于不同破坏状态的超越概率,降幅为5%～80%,改变普通转换框架结构在转换层及其相邻楼层处形成"层侧移机构"的破坏机制,有效地降低转换构件的损伤破坏,防止钢筋混凝土转换框架结构发生整体与局部倒塌破坏.由于耗能腋撑对框架柱产生较大附加剪力,建议转换构件采用钢-混凝土组合构件,形成带耗能腋撑型钢混凝土转换结构.

Based on the incremental dynamic analysis(IDA),the seismic fragility of RC(Reinforced Concrete) transfer frame structures with and without energy dissipation haunch braces(EDHBs) was investigated,and the corresponding fragility curve equations were established.The seismic reliability of the structure with EDHBs was then evaluated,and the influences of buckling-restrained EDHBs on the failure mechanism of the structure were ana-lyzed.The results show that,by setting buckling-restrained EDHBs,the exceeding probability of the RC transfer frame structure in different damage states decreases by 5%~80%;and that EDHBs change the soft-storey failure mechanism at the transfer storey and the neighboring stories and effectively alleviate the damage of transfer components,thus preventing the structure from global and local collapses.In addition,as EDHBs may result in large additional shear force on the RC column,steel-concrete composite components are more feasible in constructing steel-reinforced concrete transfer structures with EDHBs.