【摘要】 使用接触单元建立三峡库首区断裂展布有限元模型,使用确定性的设定地震方法,为时程分析提供合理的水库地震动输入。二维有限元水平基岩地震动模拟结果表明,九畹溪断裂发生M5.5级构造型水库地震时,三峡大坝场址水平向基岩PGA为175Gal;而高桥断裂发生M5.5级地震时,巴东县城场址水平向基岩PGA为303Gal。断裂带两侧PGA出现明显的不连续特征,场址基岩地震动参数的计算有必要考虑该影响。更多还原

【Abstract】 The contact algorithm was applied to construct a 2-dimension FEM simulation model which indudes the active faults.We explore a proper scenario earthquake parameter setting for the NGA model in oder to supply the input time history.We find that the horizontal bedrock ground PGA at the Three Gorges Dam project is about 175 Gal when the M5.5reservoir induced earthquake occourred on Jiuwanxi fault.A M5.5earthquake caused by Gaoqiao fault will make the horizontal bedrock ground PGA at the Badong rise to 303 Gal.We also find that the bedrock ground motion PGA on both sides of faults distributes discontinuously.This phenomenon indicates that it is necessary to consider the fault when we calculate the bedrock ground motion parameters.更多还原