典型土层场地随机地震反应规律分析

Analysis of Stochastic Seismic Response in Typical Soil Sites

针对硬、中、软3种土层场地,选取历史上实测到的Ⅰ类和Ⅱ类场地的地震动记录各100条,分别调整地震动记录加速度峰值至0.1g、0.2g和0.3g,并采用一维等效线性化方法开展了场地随机地震反应研究,系统分析了地震动峰值加速度、速度和位移反应的变异性规律。主要结论为,位移和速度峰值的变异性随场地土变软而增大;位移和速度峰值变异性较加速度峰值的变异性更为突出;利用50条左右的地震动记录即可获得场地地震反应均值和标准差较为稳定的结果。

For the hard, medium and soft soil sites, the ground motion of the class I and class II bedrock site were selected from measured data in history and each group contained 100 ground motions. The peak acceleration of ground motion records were adjusted to 0.1g, 0.2g and 0.3g, then the stochastic seismic response of the site was studied by using the one dimensional equivalent linearization method to analysis systematically the variability law of peak ground acceleration, velocity and displacement response. We concluded out that the peak value of the displacement and the velocity variability will increase when soil becoming softer, and the peak value of the displacement and the velocity variability is more prominent than peak acceleration variability. In order to obtain stable results of the mean and standard deviation of site earthquake response about 50 ground motion records are required.