近断层地震作用下多层RC框架火灾后抗震性能分析

为研究近断层地震动特性对火灾后多层RC框架抗震性能的影响,以火灾后某多层RC框架结构为研究对象,结合火灾后现场材料的检测与鉴定报告,开展了结构火灾前后在近场有脉冲和无脉冲地震作用下的结构动力弹塑性时程分析,对比分析了近场有脉冲和无脉冲地震动特性对火灾前后RC框架结构整体的抗震性能的影响。研究结果表明:火灾后,整体结构地震响应明显大于火灾前,火灾后结构底层层间位移角在脉冲型地震和无脉冲地震作用下分别达到火灾前的1.44和1.54倍;近场脉冲型地震作用下结构响应明显大于无脉冲地震,罕遇地震作用下,近场脉冲型地震工况下的底部层间位移角相较于无脉冲地震工况增加了96.0%,火灾后更是增加了118.0%。研究成果可为多层RC框架火灾后安全性评估和加固设计提供参考。

Seismic performance analysis of multi story RC frame after fire under near fault earthquake

In order to study the influence of near fault ground motion characteristics on the seismic performance of multi-storey RC frames after fire,a multi-storey RC frame structure after fire was taken as the research object,and the structural dynamic elasto-plastic time history analysis of the structure under the near-field impulse and non pulse earthquake action was carried out by combining with the field material detection and identification report after the fire The influence of the overall seismic performance of RC frame structure before and after fire.The results show that:after the fire,the seismic response of the whole structure is significantly greater than that before the fire,and the inter story displacement angle of the bottom layer of the structure after the fire is 1.44 and 1.54 times of that before the fire under the action of impulsive earthquake and non pulse earthquake,respectively;The results show that the structural response under near-field impulse earthquake is significantly greater than that under non pulse earthquake.Under rare earthquake,the bottom story drift angle under near-field pulse earthquake condition increases by 96.0%compared with that under non pulse earthquake condition,and increases by 118.0%after fire.The research results can provide reference for safety assessment and reinforcement design of multi-storey RC frame after fire.