多向动力耦合激励下隔震结构连续倒塌性能分析

为分析隔震结构在多向动力耦合激励下的连续倒塌动力响应及抗倒塌能力，建立了隔震结构在多向动力耦合激励下的运动方程，对比分析了隔震结构仅考虑竖向不平衡荷载作用与考虑多向动力耦合激励下的倒塌动力响应，基于二次四阶矩可靠度理论建立随机鲁棒性指标，并利用该指标对隔震结构抗倒塌能力进行评判。研究结果表明：隔震结构在多向动力耦合激励下，其倒塌动力响应更大；支座瞬时失效后，结构内力重新分布达到新的平衡所需时间更长；结构抗连续倒塌能力更弱。

PROGRESSIVE COLLAPSE PERFORMANCE OF ISOLATED STRUCTURES SUBJECTED TO MULTI-DIRECTION COUPLED DYNAMIC EXCITATION

In order to analyze the progressive collapse dynamic response and collapse resistance of an isolated structure subjected to multi-directional coupled dynamic excitations,the motion equation of an isolated structure under this occasion is established. The nonlinear dynamic responses of the isolated structure considering only vertical imbalance and multi-directional dynamic coupling excitations are analyzed, and a random robustness index based on reliability theory were derived to evaluate the progressive collapse ability of the isolated structure. The results show that the dynamic response of the isolated structure is greater under a multi-directional dynamic coupling excitation. After bearing fails, the time required for the internal force redistribution of the structure to reach a new equilibrium is longer, and the collapse resistance of the structure is lower.