【摘要】 本文提出了不规则地形地震响应分析的自由场计算方法,并以小湾拱坝场址作为三维场地模型,比较了三维不规则场地侧边界自由场的精确解和近似解;同时,采用大型有限元软件Ansys/Ls-Dyna计算了自由场对场地内部场点地震响应的影响。计算结果表明,三维场地模型的二维自由场近似解与精确解有很大差异,其结果对三维场地内部场点地震响应影响显著,因此,要准确求解三维不规则地形的地震响应必须采用真实的二维侧边界模型。更多还原

【Abstract】 The calculating method of lateral boundary’s free field for 3D irregular topography is presented in this paper,and then Xiaowan arch dam’s site is selected as a 3D element model.The exact solution and approximate solution of lateral boundary’s free field are found and compared.At the same time,the influence of different free field’s calculating methods on the seismic responses of internal field is simulated by large finite element software Ansys / Ls-Dyna.The results show that big differences exist between the exact solution and the approximate solution,and the different results lead to significant changes in the seismic responses of 3D site.Therefore,the real two-dimensional lateral boundary model must be adopted in the problem of seismic responses for 3D irregular topography.更多还原