基于节点冲切破坏的板柱结构连续倒塌可靠性分析

从结构体系可靠度的角度认识钢筋混凝土板柱结构的抗连续倒塌性能,用Monte-Carlo连续成组抽样方法对以节点冲切破坏为主的板柱结构连续倒塌进行可靠度分析。在建立板柱节点功能函数的基础上,推演了抗冲切承载力分布及荷载基本变量分布和荷载效应组合的方法。通过计算初始条件下任意一个板柱节点失效的概率和一个节点失效条件下其他节点失效的条件概率,分析了不同位置板柱节点在抗连续倒塌中的重要性以及板柱结构的抗连续倒塌鲁棒性指标。结果表明:底层中柱节点冲切失效最容易引起其他节点的连续性破坏及倒塌,按我国规范设定了柱顶贯通受压钢筋的板柱结构鲁棒性指标比较高。

RELIABILITY ANALYSIS FOR PROGRESSIVE COLLAPSE OF SLAB-COLUMN STRUCTURE BASED ON THE PUNCHING FAILURE OF THE CONNECTION

In this paper, the behavior of progressive collapse-resistance of reinforced concrete slab-column structures was investigated from the view of system reliability. The Monte-Carlo method with continuous group sampling was used to analyze the reliability of progressive collapse of the slab-column structure. The slab-column structural performance function was established, the probability distributions of punching resistance of the slab-column connection and loads were obtained, and the load combination was determined. The failure probability of one slab-column connection was calculated, and the conditional failure probability of one slab-column connection given another one connection fails was also calculated; And then the importance of one slab-column connection on the progressive collapse-resistance of the slab-column structure and the robustness index in progressive collapses-resistance were analyzed. The calculation results show that the progressive collapse most likely occurs when a middle slab-column connection fails, and the robustness of reinforced concrete slab-column structure with continuous steel bars on the top of the slab designed according to Chinese Code is acceptable.