【摘要】 目前结构抗震分析时使用的地震动强度指标较多,各种地震动强度指标的适用性尚未有统一的定论,缺乏系统的分析。采用考察结构最大地震响应与地震动强度指标之间的线性相关性的方法,选取具有代表性的100条原始地震动记录作为输入,基于不同周期的SDOF系统和实际减隔震桥梁,研究各地震动强度指标与结构地震响应的相关性。根据研究结果,将地震动强度指标划分为4类,其中以Sa(T1)为代表的第Ⅰ类强度指标与不同周期结构的相关程度都较高,而以PGA为代表的第Ⅱ类和以PGD为代表的第Ⅲ类强度指标分别对短周期和长周期结构的相关程度较高,以PGV为代表的第Ⅳ类强度指标相对较稳定,建议采用第Ⅰ类强度指标作为衡量地震动强度的指标参数。并通过工程实例进一步论证了对于自振周期已知的结构,地震动的不同强度指标与结构地震响应的相关性不同。更多还原

【Abstract】 Many ground motion intensity indexes are used to the structure aseismic analysis,but there are no unified final conclusion and lack of systematical analysis for the applicability of these indexes. Here,the correlation between ground motion intensity and structural seismic response was investigated by inputting 100 typical ground motion records in to SDOF systems and seismic-isolation-and-reduction continuous-beam bridges having different periods. The results showed that the intensity indexes can be separated into four groups; the group I of indexes represented with Sa( T1)has a higher correlation with structures of different periods; the group II of indexes represented with PGA has a higher correlation with short period structures; the group III of indexes represented with PGD has a higher correlation with middle period structures; the group IV of indexes represented with PGV has a relatively stable correlation with structures. The group I of indexes was suggested to be taken as the ground motion intensity index. A practical engineering analysis showed that different intensity indexes have different correlation with structures having the known natural vibration periods.更多还原