特征周期相关性分析

特征周期是反应谱曲线下降段起点对应的周期,是建筑抗震设计重要参数。研究6种基于地面运动记录确定特征周期的方法,即ATC3-06方法、ASCE7-16方法、概率法(97%)、峰值法、峰值折减法、平滑法,采用1 491条地面运动记录,对比它们的特征周期分布,研究不同方法、不同地震事件对特征周期分布的影响,分析6种计算方法的相关性。分析结果表明,ATC3-06特征周期映射了区段谱速度与区段谱加速度之比,ASCE7-16特征周期在简化区段谱速度与区段谱加速度之比的基础上考虑了场地因素影响,概率法(97%)以反应谱特征周期下包含的面积比映射特征周期;6种计算方法8次地震计算的特征周期主要分布在0.2～1.2 s,占总数的80%,不同地震特征周期在0.2～1.2 s区间内的分布具有差异性,反映出场地特征;ATC3-06方法、ASCE7-16方法、概率法(97%)、峰值折减法、平滑法之间有较好的相关性。

Correlation Analysis of Characteristic Periods

Six methods for the determination of characteristic period based on ground motion records were studied in this paper, i.e., ATC3-06 method, ASCE7-16 method, probability method (97%), peak value method, peak value reduction method, and smoothing method. The distribution of characteristic periods obtained by these six methods were compared by using 1 491 ground motion records. The influence of different calculation methods and different seismic events on the distribution of characteristic period were studied, and the correlation of these methods was also analyzed. The results showed that ATC3-06 characteristic period reflects the ratio between sectional spectral velocity and sectional spectral acceleration, while ASCE7-16 characteristic period considers the influence of site factors based on the ratio between simplified sectional spectral velocity and sectional spectral acceleration; Probability method (97%) reflects the characteristic period with the area ratio contained in characteristic period of response spectrum. The calculated characteristic periods of eight earthquakes calculated by six methods are distributed mainly from 0.2 s to 1.2 s, accounting for 80% of the total. There is a good correlation among ATC3-06 method, ASCE7-16 method, probability method (97%), peak value reduction method, and smoothing method.