城市轨道交通大跨度钢管混凝土柱车站地震易损性仿真分析

Seismic Vulnerability Simulation Analysis of Urban Rail Transit Large-span Concrete-filled Steel Tube Column Station

为提升城市轨道交通车站的建筑功能,目前设计采用钢管混凝土柱且加大柱距是常见的一种手段。为此,需要对大跨度钢管混凝土柱车站的地震易损性进行研究,并对比分析钢管混凝土柱与传统钢筋混凝土柱的受力特点及抗震性能。以我国南方某采用钢管混凝土柱的城市轨道交通车站为原型,采用Midas GTS NX软件建立三维计算模型,对其地震易损性进行研究。采用静力推覆法确定车站结构的损伤指标;选择10条天然地震波,对车站结构进行增量动力分析,得到车站在各地震作用下的相对位移角;将增量动力分析的结果进行对数正态分布拟合,得到车站的地震易损性曲线。结果表明:地震峰值加速度为0.8 g(g为重力加速度)时,钢管混凝土柱车站结构发生轻微破坏的概率为83.46%,发生严重破坏的概率为15.21%,发生毁坏的概率为4.26%。相较于常规混凝土框架结构车站,钢管混凝土柱车站的抗震性能更好。

To improve the functionality of urban rail transit station design,the use of CSFT(concrete-filled steel tube)column with increased column spacing is a common approach.The seismic vulnerability of a large-span CSFT column station needs to be studied,and the stress characteristics and seismic performance of CSFT columns need to be compared with conventional reinforced concrete columns.Taking an urban rail transit station with CFST column in southern China as prototype,a 3D calculation model is established using Midas GTS NX software,and its seismic vulnerability is studied.The static pushover analysis method is used to determine the station structure damage indexes.10 natural seismic waves are selected,and IDA(incremental dynamic analysis)is performed to obtain the relative displacement angles of the station under various seismic actions.The results of the IDA are fitted to a logarithmic normal distribution to obtain the seismic vulnerability curve of the station.Results show that when the peak seismic acceleration is 0.8 g(g as the gravitational acceleration),the probability of slight damage to the CFST station structure is 83.46%,the probability of severe damage is 15.21%,and the probability of collapse is 4.26%.Compared with a common concrete frame structure station,CFST column station demonstrates better seismic performance.