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地震地面效应是地震工程和工程地震工作者共同关心的问题.前者着重研究地震动对上部结构的影响,后者则主要从事研究地震动对场地地基工程地质条件的影响.1979年对北京市区所作的一维地震反应分析,得出了土层厚度是影响地震地面运动的主要因素.输入地震动的卓越周期及其加速度峰值对反应谱形状的影响较时程曲线的影响明显.但一维方法只反映有界水平层及地震垂向上传.二维动力有限元地震反应分析改进了上述局限性,它可以研究任意形状的地基地质结构,能够反映埋藏基岩地形对地震波的折射、反射所产生的能量聚、散效应,埋藏基岩地形对地震地面效应的影响比上复松软土层土质不均匀的影响要大.超声地震模型实验首次引入工程地震学的研究课题中,得到了与上述数值分析方法相似的结果,并提出若干新问题.它提供了一种能够全面模拟震源—传播途径—场地地质结构的综合研究方法.
Earthquake ground effect is a common concern of earthquake engineering and engineering earthquake workers, the former focuses on the impact of ground motion on the superstructure, while the latter is mainly engaged in the study of the impact of ground motion on the engineering geological conditions of the site .In 1979, The results show that the thickness of soil layer is the main factor affecting the ground motion of the earthquakes.The influence of the excellent period of input ground motions and its acceleration peak on the shape of response spectrum is more significant than that of the time history curve, The method only reflects the bounded horizontal layer and vertical seismic uploading.The 2D dynamic finite element seismic response analysis ameliorated the above limitations, which can study the geological structure of any shape and can reflect the refraction and reflection of the seismic waves by the buried bedrock topography The effect of polygons and scattered energy produced by buried bedrock on seismic ground effect is greater than the effect of uneven soil quality in upper soft soil.Ultrasonic seismic model experiment was first introduced into the research project of engineering seismology, Numerical analysis of similar results and raised a number of new issues.It provides a comprehensive simulation of source - Broadcast approach - a comprehensive study of the geological structure of the field method.