基于弹塑性时程分析的结构地震倒塌时间研究

Seismic Collapse Time of Structures Based on Elastoplastic Time-history Analysis

地震过程中建筑倒塌前的时间段,是人员逃生的重要阶段,研究结构地震倒塌时间规律对人员倒塌逃生避险有重要的意义。针对地震逃生方法研究的需要,基于RC框架结构的典型倒塌模式建立简化结构模型;将60条不同特性的人工地震波输入到8个结构模型得到弹塑性时程分析结果,再以结构损伤指数为1的条件求得结构地震倒塌时刻;利用假设的双重调节模型和回归分析方法,对地震波峰值加速度、特征周期和结构自振周期等因素与倒塌时间的关系进行了研究,结果表明,特征周期和结构自振周期在峰值加速度对倒塌时间的影响中存在双重调节效应;整理已有研究文献的倒塌试验结果与回归模型对比,验证弹塑性时程计算对倒塌时间估算的可行性。

The time before the collapse of buildings in earthquake is an important stage for people to escape.It is of great significance to study the collapse time rule of structures in earthquake for people to escape from collapse.Based on the typical collapse mode of RC frame structure,a simplified structure model is established for the study of earthquake escape methods.The elastoplastic time-history analysis results are obtained by inputting 60 artificial seismic waves with different characteristics into 8 structural models,and then the collapse time of the structure is obtained by taking the structural damage index as 1.The relationship between peak acceleration of seismic wave,characteristic period and natural vibration period of structure and collapse time is studied by using the assumed double regulation model and regression analysis method.The results show that the characteristic period and natural vibration period of structure have double regulation effect in the influence of peak acceleration on collapse time.To verify the feasibility of collapse time estimation by elastic-plastic time history calculation,the collapse test results of existing research literature are compared with regression model.