爆炸下钢柱破坏时间及残余承载力对钢框架连续倒塌的影响  

Effects of Steel Column's Failure Time and Residual Bearing Capacity on Progressive Collapse of Steel Frames Subjected to Blast

作　　者：李国强[1,2] 杨涛春[2,3] 陆勇[4] 陈素文[1,2] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092 [2]同济大学土木工程学院,上海200092 [3]济南大学土木建筑学院,山东济南250022 [4]爱丁堡大学工程学院

出　　处：《湖南大学学报（自然科学版）》2016年第5期1-8,共8页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金国际合作与交流项目(51120185001)~~

摘　　要：建立钢框架连续倒塌单自由度(SDOF)分析模型,研究钢柱破坏时间及其残余承载力对钢框架连续倒塌的影响规律,发现钢柱破坏时间越长、残余承载力越大,结构位移响应越小.以SDOF模型响应的理论解为基础,得出在钢框架倒塌计算中是否考虑钢柱破坏时间的界限标准:当钢柱破坏时间与连续倒塌的SDOF模型周期比τ<0.2时,可忽略破坏时间的影响;当τ>3.0时,可采用静力方法计算结构响应;当0.2<τ<3.0时,需考虑破坏时间对结构连续倒塌的影响.通过对钢柱等效SDOF模型的理论分析,当其抗力模型分别为理想弹塑性和刚塑性条件时,求得柱子破坏时间的近似计算方法,并以爆炸作用后柱子变形为初始状态,结合数值方法给出钢柱残余承载力计算过程.通过对钢柱的破坏时间和残余承载力对结构倒塌影响的算例分析,表明钢柱的破坏时间(越长)和残余承载力(越大)对结构抗倒塌起有利作用,在结构抗倒塌计算时不可忽略.The influence law of failure time and residual bearing capacity of the steel columns on pro- gressive collapse of steel frames was studied by using a single degree of freedom （SDOF） model. The dis- placement of the steel frames decreases as the failure time and residual bearing capacity of the steel columns increase. On the basis of the theoretical solution of the SDOF model, boundary condition of the model was determined to consider the failure time effect, r was defined as the ratio of the failure time to natural period of the SDOF model. For τ〈0.2, the failure time can be ignored. For τ〉3.0, a static method can be used to estimate the structure behavior. However, for 0.2〈τ〈3.0, the failure time should be considered in the progressive collapse analysis. When the resistance model is ideal elastic-plastic and rigid-plastic, the equivalent SDOF model of the steel columns can be theoretically analyzed to determine the calculation method of the failure time. Considering the deformation of the steel columns after explosion as the initial state, the calculation process for the residual bearing capacity of the steel columns is gained by combining with nu- merical calculations. The results show that the failure time and residual bearing capacity significantly influ- ence on the progressive collapse of the steel frames, and those effects should be considered in the progres- sive collapse analysis.

关 键 词：钢框架 连续倒塌 破坏时间 残余承载力 单自由度模型 

分 类 号：TU312.3[建筑科学—结构工程]