论文部分内容阅读
选择国家强震动台网中心发布的2008年5月12日汶川地震四川、甘肃、陕西等地台站中的94组加速度记录进行了处理,提取了一些主要地震动参数,应用统计分析方法重点对地震动竖向与水平峰值加速度比、竖向与水平加速度反应谱及竖向与水平卓越周期比等进行了研究。结果表明:竖向与水平峰值加速度比的平均值为0.58,但约30%台站的峰值加速度比大于2/3;竖向与水平峰值加速度比随震中距的增大减小,近震区该比值离散性较大,场地条件对该比值也有较大的影响;在周期0~6s内竖向与水平加速度反应谱比曲线总体呈马鞍形;不同的周期段,竖向加速度反应谱和水平加速度反应谱的谱形有较大差异,相比水平加速度反应谱,竖向加速度反应谱偏“瘦”;除少数台站外,绝大部分台站竖向与水平卓越周期比均小于1.0,该比值随震中距的增大而增大,并逐渐趋于平缓。上述研究结果可以为时程分析选取竖向地震动输入提供参考。
94 sets of acceleration records in stations of Sichuan, Gansu and Shaanxi of Wenchuan Earthquake, released on May 12, 2008, released by National Strong Vibration Network Center, were processed and some major ground motion parameters were extracted. Vertical and horizontal acceleration of ground motion, response spectrum of vertical and horizontal acceleration, vertical and horizontal period ratio of excellent and so on. The results show that the average value of vertical and horizontal peak acceleration ratio is 0.58, but the peak acceleration ratio of about 30% of stations is greater than 2/3. The vertical and horizontal peak acceleration ratio decreases with the increase of epicentral distance, The ratio is more discrete and the site conditions have a greater impact on the ratio. The vertical and horizontal acceleration response spectrum curves are saddle-shaped in the period of 0 ~ 6 s. In different periods, the vertical acceleration response spectrum and level Compared with the horizontal acceleration response spectrum, the vertical acceleration response spectrum is slightly “thin”. Except for a few stations, most of the station vertical and horizontal excellent period ratio are less than 1.0, the ratio increases with the epicentral distance increases, and gradually tends to be gentle. The results of the above research can provide reference for the selection of vertical ground motion input by time history analysis.