爆炸荷载下钢筋混凝土框架结构连续倒塌分析方法比较
Comparison of Progressive Collapse Analysis Methods for RC Frame ？？Structures Under Blast Loads

运用显式动力有限元分析软件LS？？DYNA建立了一个四层两跨钢筋混凝土框架结构的有限元模型，并对其施加爆炸荷载，在爆炸荷载仅引起结构关键柱失效的情况下，研究了不同比例距离爆炸荷载作用下钢筋混凝土结构的动力响应及倒塌过程；同时采用美国国防部2009年出台的建筑物抗连续倒塌设计规范UFC 4？？023？？03中推荐使用的替代传力路径法对相同的四层钢筋混凝土框架结构进行了非线性动力连续倒塌分析。通过比较研究上述数值分析结果，揭示了UFC 4？？023？？03规范推荐使用的替代传力路径分析方法的不足，进而对考虑爆炸荷载作用的结构抗连续倒塌分析设计方法的改进提出了设想。研究结果表明：通过引入爆炸荷载放大系数来考虑爆炸荷载作用的影响具有更广的适用范围。
The finite element model of a four？？storey two？？span reinforced concrete (RC) frame structure was established using the explicit dynamic finite element analysis software LS？？DYNA. In the case of only key column failure due to blast loads, the dynamic response and collapse process of the RC frame structure under blast loads of different scaled distances were studied. Meanwhile, nonlinear dynamic analysis of the same four？？storey structure was done using alternate path method recommended by the UFC 4？？023？？03 which was published in 2009 by United States Department of Defence. Through comparative study based on the numerical analysis results above, it revealed the deficiency of the alternate path analysis method. Furthermore, the proposal of the improved analysis and design method of buildings to resist progressive collapse due to blast was made. The study results show that considering the influence of blast load by introducing the blast load factor has a broader applicable scope