钢框架结构地震倒塌数值模拟方法研究

A Numerical Simulation Method on the Seismic Collapse of Steel Frame Structures

准确模拟建筑物地震倒塌可为分析建筑废墟存活空间分布规律和构建救援生命通道提供重要的前期基础。以钢框架结构为研究对象,重点讨论钢框架、填充墙、填充墙与钢框架之间连接问题。采用有限单元法(FEM)和有限-离散单元法(F-DEM)相结合的方法模拟了2跨×3跨的3层钢框架填充墙结构,以倒塌模式为评价指标来验证数值模拟方法的准确性。结果表明:数值模型整体结构表现为倾斜式倒塌模式,朝大跨度方向倒塌并伴随扭转,与实际震害中外廊式结构的倒塌模式相一致;向着结构大跨度方向的存活空间逐渐减小;倒塌层废墟内部的存活空间多呈三角形分布。提出的数值模拟方法可为钢框架结构的震后救援和地震抗倒塌设计提供一定的参考。

It is very essential to accurately simulate the seismic collapse of buildings,in order to analyze the survival space distribution law of building ruins after earthquake and build a life-saving passage. Thus,the modeling method of steel frame,infilled wall,and the connection between infilled wall and steel frame is firstly investigated. The combined finite element method(FEM)and finite-discrete element method(F-DEM)is proposed to build the numerical model of two-span by three-span and three-story steel frame structure. The evaluation criterion includes the collapse mode.The results show that the numerical simulation is consistent with the actual damage,the overall structure shows a tilting type collapse. The steel frame structure collapses towards longer spans and forms torsional failure. The survival space decreases gradually towards the longer span direction. Triangular survival spaces are mostly created inside ruins. Therefore,the combined FEM and F-DEM is valuable in simulating steel frame structure for the postearthquake rescue and anti-collapse design.