This paper deals with seismic response evaluation of a finite multilayered geological structure with non-parallel boundaries rested on semi-infinite elastic half-plane subjected to transient seismic wave. The hybrid modelling approach is applied. It is based on the decomposition of the whole domain under consideration into two subregions: a finite-sized near-field zone and the open semi-infinite far-field region. The near-field range is presented by a finite geological profile, which is heterogeneous due to non-parallel layering. The far-field region is semi-infinite elastic isotropic homogeneous medium where the finite layered structure is located. An efficient 2D hybrid computational tool based on the boundary element method (BEM) for the far-field zone and the finite element method (FEM) for the finite layered domain is developed and verified in frequency domain. The BEM model of the seismically active far-field zone is inserted as a macro-finite element (MFE) in the FEM commercial program ANSYS. The hybrid model is of the FEM hosted type, where the boundary element domain (BED) is converted into macro-finite element, the nodal forces along the interface between two zones are expressed through the BED nodal tractions and the entire BEM formulation is converted to FEM-like approach. This hybrid model is applied for modelling of a real geological profile of the main wall of the “Liulyakovitsa” tailing pond, near Panagyurishte town, Bulgaria. Simulation results are given in the form of free surface synthetic seismograms stemming from the real seismic signals recorded at bedrock so as to establish the tailing pond’s seismic response.

中文翻译：

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地震激励下多层地质结构的混合建模

本文研究了半无限弹性半平面受瞬态地震波作用下边界不平行的有限多层地质结构的地震反应评价。应用了混合建模方法。它基于将所考虑的整个域分解为两个子区域：有限大小的近场区域和开放的半无限远场区域。近场范围由有限的地质剖面表示，由于不平行的分层，该剖面是不均匀的。远场区域是有限层结构所在的半无限弹性各向同性均匀介质。基于频域的边界元方法（BEM）和有限分层域的有限元方法（FEM），开发了一种高效的二维混合计算工具。在FEM商业程序ANSYS中，将地震活动远场区域的BEM模型作为宏有限元（MFE）插入。混合模型属于FEM托管类型，其中边界元素域（BED）转换为宏观有限元，沿着两个区域之间的界面的节点力通过BED节点牵引力表达，整个BEM公式转换为类似于FEM的方法。该混合模型用于对保加利亚Panagyurishte镇附近的“ Liulyakovitsa”尾矿池主墙的真实地质剖面进行建模。