钢管混凝土组合框架抗连续倒塌鲁棒性初步分析

为研究钢管混凝土框架结构的竖向连续倒塌易损性,设计了一个8层4×4 跨钢管混凝土柱-钢梁空间框架,利用有限元软件ABAQUS,采用静力加载方法,对原结构及拆除各底层柱后的剩余结构进行模拟研究;在已有改进后的两种基于构件重要性的易损性分析方法的基础上,分别计算结构构件的重要性系数;并计算了双柱失效工况下结构的鲁棒性系数,分析了该类结构的竖向鲁棒性.结果表明:两种方法计算结果相近,构件重要性系数的变化趋势一致;外荷载的增加与结构鲁棒性呈负相关,角柱相对边柱和中柱较为重要;角柱与边柱同时失效时,结构发生倒塌的几率大大提升.实际中可采用备用荷载路径的方法对重要性系数较大的构件进行低易损性设计.

Preliminary analysis of robustness of progressive collapse of composite frame with CFST column

In order to study the vertical progressive collapse vulnerability of CFST frame structures, an 8-story CFST frame with 4×4 span was analyzed. The finite element software ABAQUS and the Pushdown analysis method were used to simulate the original structure and the remaining structure after the removal of each bottom column. Based on the two improved vulnerability analysis methods considering the component importance, the importance coefficients of structural components were calculated separately, and the robustness coefficients of the structure under double-column failure conditions were calculated to analyze the vertical robustness of this kind of structure. The results show that the calculation results of the two methods are similar, and the change trend of the component importance coefficient is the same The increase in external load is negatively correlated with the structural robustness. The corner column is more important than the side column and center column. When corner posts and side posts fail at the same time, the chance of the structure collapsing is greatly increased. The alternate path method can be choosed in low-fragility designation for components with large importance coefficient.