3D dynamic interaction of two adjacent elastic foundations embedded in a finite layered soil region rested in a homogeneous elastic isotropic half-space with a transient dynamic source is studied. The hybrid computational model, the corresponding numerical scheme and the accompanied software are developed, verified and inserted in detail parametric study. The hybrid approach is based on (a) finite element method (FEM) describing the scattered wave field in a finite layered soil profile with two foundations; (b) boundary element method (BEM) considering waves radiating from a dynamic transient source in elastic semi-infinite range. The aim is to propose an efficient hybrid methodology for evaluation of the dynamic response of a foundation-soil-foundation system, taking into account (a) the whole wave path from the dynamic source, through the layered soil region, till the underground structures; (b) the damage state of the geological material. The BEM model is based on the 3D elastodynamic fundamental solution in Fourier domain and it is applied in order to obtain frequency-dependent stiffness matrix and load vector of the dynamically active semi-infinite geological zone. Once the BEM model is formulated, it is inserted as a macro-finite element in the FEM software package ABAQUS. The frequency-dependent FEM model describing the wave field in finite layered soil profile with two elastic foundations is realized by ABAQUS. Solutions in time domain are obtained through application of the inverse fast Fourier transform. As a final result an efficient hybrid model comprising all in one: dynamic (seismic or other type) source-homogeneous elastic half-space-finite heterogeneous by layers and foundations soil profile, is presented. Parametric study illustrating the sensitivity of the dynamic field to key factors such as the type and properties of the load, the soil layering, the material properties of the far- and near-field soil regions, the damaged state of the geological material and the foundation-soil-foundation interaction is shown and discussed.

中文翻译：

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地基-土-地基动力相互作用的3D混合模型

研究了嵌入有限分层土壤区域中的两个相邻弹性基础的 3D 动力相互作用，该区域位于具有瞬态动力源的均匀弹性各向同性半空间中。混合计算模型、相应的数值方案和配套软件被开发、验证和插入详细的参数研究。混合方法基于 (a) 有限元法 (FEM) 描述具有两个基础的有限分层土壤剖面中的散射波场；(b) 边界元法 (BEM) 考虑从弹性半无限范围内的动态瞬态源辐射的波。目的是提出一种有效的混合方法来评估地基-土-地基系统的动态响应，同时考虑 (a) 来自动态源的整个波路径，穿过分层的土壤区域，直到地下结构；(b) 地质材料的破坏状态。BEM 模型基于傅立叶域中的 3D 弹性动力学基本解，用于获得动态活动半无限地质带的频率相关刚度矩阵和载荷矢量。一旦建立了边界元模型，它就作为宏观有限元插入到有限元软件包 ABAQUS 中。用ABAQUS实现了描述具有两个弹性地基的有限层状土壤剖面中波场的频率相关有限元模型。通过应用逆快速傅立叶变换获得时域中的解。作为最终结果，一个高效的混合模型包含了所有功能：动态（地震或其他类型）源均匀弹性半空间有限异质层和地基土壤剖面，呈现。参数研究说明动态场对关键因素的敏感性，例如载荷的类型和特性、​​土壤分层、远场和近场土壤区域的材料特性、地质材料和地基的损坏状态- 显示和讨论了土壤-地基相互作用。