Abstract: The effect of underlying bedrock slope on the seismic ground motion is indicated by the seismic microregionalization for the study area.Two-dimentional inversion has been used in the seismic model and the author has worked out an extending program SAP 5.The main results are as follows:vertical ground motion is significant;distributions of horizontal motion vary with the distance of the bedrock from the center of the basin;the spectra show a regular variation;input of multi-directional seimic waves shows larger effect than does input of mono-directional seismic waves on the ground motion.As indicated by data the effect of underlying bedrock slope on the ground motion is significant compared with the site condition.

摘要： 本文在分析了徐州地区地震地质背景的基础上,用经作者扩展的SAP 5程序,重点分析了地震小区划中提出的埋藏基岩斜坡地形对地震地面运动的影响问题。初步认识到:这种复杂地形可产生不可忽视的竖向运动;水平向运动分布依其与基岩山丘的距离而不同;地震反应谱形状呈有规律的变化;输入多方向震波的影响比输入单方向震波时的影响要大。