钢筋混凝土抗震框架连续倒塌行为分析

以某抗震设防框架为研究对象，采用S A P2000有限元软件，依次拆除底层纵向边柱、横向边柱、角柱和内柱，研究抗震框架的倒塌破坏行为。以做功平衡原理建立了柱失效处梁配筋调整计算公式，并进行了配筋调整设计。结果表明：7度和8度抗震设防的框架结构仍会发生连续性倒塌，但是抗倒塌能力随着设防等级的提高而提高，抗震设计不能够完全替代抗倒塌设计；柱失效导致结构发生连续坍塌破坏的危险性由小到大依次为内柱、横向边柱、纵向边柱、角柱；梁铰机制在结构抗倒塌中的作用尤其重要，倒塌破坏时以梁的弯曲破坏为主，剪切破坏较少出现；线弹性静力分析计算的供需比最大值一般出现在失效柱上一层的相邻梁上，而非线性静力分析的最大破坏出现在与失效柱相连的梁上，但是二者对结构可能的失效位置判断基本一致。

Analysis of Progressive Collapse Behavior of Earthquake-resistant Reinforced Concrete Frame

Using the finite element software SAP2000 , progressive collapse behavior of the earthquake‐resistant reinforced concrete （RC ） frame was investigated when its longitudinal peripheral‐column , transverse peripheral‐column , corner‐column , and interior‐column were removed in turn .Based on energy balance principle ,the formula of the adjustment of the steel bars of the beams connected with the failure column was proposed ,and the adjustment design was done .The results show that RC frame structures in zones with seismic intensity Ⅶ or Ⅷcould develop progressive collapse ,but their collapse resistance will improve with the increasing of their seismic performance levels ,and seismic design can not eventually replace anti‐collapse design .The dangers of the structure progressive collapse caused by column failure from small to big is interior‐column removing ,transverse peripheral‐column removing ,longitudinal peripheral‐column removing ,corner‐column removing .The beam‐hinge mechanism is especially important in the collapse of the structures .The main failure is the bending failure of beams ,not the shear failure of beams , w hen the collapse happens . T he maximum value of the ratio of supply and demand calculated with the linear elastic static mechanical analysis method appears in the beams which connect the column that is above the failure column .Moreover ,the greatest damage of the structure analyzed with nonlinear static mechanical analysis method appears in the beams which connect with the failure column .But the two results of the judgment of the structure＆#39;s failure position are basically identical .