Soil-structure interaction problems are an important issue in the research field of geotechnical engineering. Understanding and modeling the soil-structure interaction problems is thus critical. Such interaction problems involve the mechanical behaviors of both soil and structure as well as their complex interaction. Discontinuous deformation method (DDA) is appropriate for modeling mechanical behavior of structure, while smoothed particle hydrodynamics (SPH) offers a feasible technique for describing the mechanical behavior of soil material. A coupled DDA-SPH method can integrate the advantages of both DDA and SPH. For three-dimensional (3-D) dynamic analysis of the soil-structure interaction problems, the original 3-D coupled DDA-SPH method must be extended, which is the primary purpose of this paper. In the extended 3-D coupled DDA-SPH method, an elastic-plastic soil constitutive model associated with the Drucker-Prager yield criterion is implemented. The interaction between soil and structure is realized through a newly proposed coupling scheme based on a penalty method using the Mohr-Coulomb failure criterion. Furthermore, the extended 3-D coupled DDA-SPH method is validated through the investigation of four experiments. The simulation results suggest that the extended 3-D coupled DDA-SPH method can accurately simulate the large deformations and post-failure behavior of soil-structure interaction problems.

土-结构相互作用问题是岩土工程研究领域的一个重要问题。因此，理解和模拟土壤-结构相互作用问题至关重要。这种相互作用问题涉及土壤和结构的力学行为以及它们复杂的相互作用。不连续变形法（DDA）适用于模拟结构的力学行为，而平滑粒子流体动力学（SPH）为描述土壤材料的力学行为提供了一种可行的技术。耦合的 DDA-SPH 方法可以综合 DDA 和 SPH 的优点。对于土结构相互作用问题的三维（​​3-D）动力分析，必须扩展原有的3-D耦合DDA-SPH方法，这是本文的主要目的。在扩展的 3-D 耦合 DDA-SPH 方法中，实施了与 Drucker-Prager 屈服准则相关的弹塑性土本构模型。土壤和结构之间的相互作用是通过一种新提出的耦合方案来实现的，该方案基于使用 Mohr-Coulomb 失效准则的惩罚方法。此外，通过对四个实验的调查验证了扩展的 3-D 耦合 DDA-SPH 方法。模拟结果表明，扩展的3-D耦合DDA-SPH方法可以准确模拟土-结构相互作用问题的大变形和破坏后行为。此外，通过对四个实验的调查验证了扩展的 3-D 耦合 DDA-SPH 方法。模拟结果表明，扩展的3-D耦合DDA-SPH方法可以准确模拟土-结构相互作用问题的大变形和破坏后行为。此外，通过对四个实验的调查验证了扩展的 3-D 耦合 DDA-SPH 方法。模拟结果表明，扩展的3-D耦合DDA-SPH方法可以准确模拟土-结构相互作用问题的大变形和破坏后行为。