论文部分内容阅读
以玉树7.1级地震中某底层遭到严重破坏的钢筋混凝土(RC)框架结构为原型,设计了1个1∶5缩尺的三维模型,通过模型的倒塌全过程振动台试验,研究了汶川、玉树地震中高烈度地区RC框架结构出现的典型侧向逐层呈多米诺骨牌式连续倒塌现象的全过程和倒塌破坏机制。试验中该模型结构的倒塌过程共分为两个阶段,即侧向增量倒塌和竖向连续倒塌。当底层层间位移角达到1/19时,试验模型处于临近倒塌状态。在倒塌过程中,底层角柱C3最先丧失竖向承载力,此时竖向倒塌开始发展,结构在重力荷载及输入地震动的共同作用下,底层柱的水平侧移持续增加,造成其相邻的柱B2、B3、C2相继失效,丧失竖向承载力,模型结构的冗余度不足使结构产生更大范围的竖向倒塌,最终模型结构呈侧向逐层连续倒塌。通过对倒塌后废墟的研究,发现模型结构呈“强梁弱柱”型破坏,其破坏模式与震害调查结果一致。最后,讨论了此种废墟下人员生存空间的问题,给出了防RC框架结构倒塌的相关建议。
A 1: 5-scale three-dimensional model was designed based on the RC frame structure, which was severely damaged by some ground floor in the Yushu 7.1 earthquake. Through the shaking table test of the whole process of the collapse of the model, The typical lateral layer-by-layer domino-type collapse phenomenon occurred in RC frame structure in high-intensity area of Yushu earthquake and the collapse failure mechanism. During the experiment, the collapse of the model structure is divided into two phases, namely lateral incremental collapse and vertical continuous collapse. When the displacement angle between the bottom layers reaches 1/19, the test model is in a state of collapse nearby. In the process of collapse, the bottom corner column C3 firstly loses the vertical bearing capacity, and then the vertical collapse starts to develop. Under the combined action of gravity load and input ground motion, the lateral displacement of the bottom column continues to increase, resulting in its adjacent Of the columns B2, B3, C2 have failure, loss of vertical bearing capacity, the lack of redundancy of the model structure to a greater extent of the vertical collapse of the structure, the final model structure was a lateral layer by layer continuous collapse. Through the research on the ruins after the collapse, it is found that the model structure is “strong beam weak column ” type failure, and its failure mode is consistent with the earthquake damage investigation. Finally, the problem of living space under such rubble is discussed, and some suggestions about the collapse of RC frame structure are given.