目前随着工程技术的发展，我国的地下空间开发利用不断推进，而地下结构抗震是一个需要解决的关键问题。地下结构处于土中，对其地震的响应规律的研究需要对土体-地下结构体系进行计算分析，尤其对于可液化土体中的结构而言，因此对大规模流固耦合仿真计算也提出了更高的要求。同时，随着海量仿真数据的出现，如何进行高效合理的后处理并以可视化方式展现，也成了大规模岩土仿真亟待解决的一个问题。本文针对上述两个问题：大规模岩土流固耦合仿真与可视化，进行了相应的探索与研究，前者基于已有平台进行液化大变形本构开发及相关完善，后者则基于Unity3D引擎开发了相应的可视化解决方案。论文的主要成果与结论包括：（1）基于高性能数值仿真平台GEOSX，添加了砂土液化大变形CycLiqCPSP本构模型应力积分模块，开发补充了包括不同材料分区求解、捆绑边界约束、孔压边界条件等模块，可以实现基于CycLiqCPSP模型的大规模动力流固耦合仿真。研究通过三轴排水与不排水试验、一维土柱动力响应及二维土体动力响应试验，验证了所开发的CycLiqCPSP模型流固耦合计算的有效性。（2）基于Unity3D引擎开发了针对岩土工程的大规模仿真可视化软件GIV，用于处理岩土工程大规模仿真产生的海量数据。其中，GIV的预处理模块可以有效压缩大规模仿真数据，为轻量化便携式海量数据可视化提供可能；可视化模块优化了数据获取方式、交互方式等，提高了可视化过程的效率和交互友好性。研究通过一系列理想模型与实际计算模型的对比试验，证明了GIV在处理大规模岩土仿真可视化上的有效性。（3）将研究开发的一系列大规模仿真及可视化方案应用于自由场地和地下工程仿真计算及后处理中。在应用研究中，通过对模型的变形、应力应变等分析，验证了上述大规模动力流固耦合方案的适用性与准确性；通过对相应数据的预处理分析及可视化统计，证明了上述可视化方案在处理大规模岩土仿真可视化中的高效性与便捷性。总结起来，本研究针对大规模岩土动力流固耦合仿真，提出并实现了一套由仿真计算到可视化后处理的解决方案。
With the development of engineering technology at present, the underground space development in China is continuously promoted. However, the underground structure has been plagued by earthquake disaster since it emerged. Because the underground structure is in the soil, the response law of the earthquake needs to calculate and analyze the soil and underground structure system (especially for the structure in the liquefiable soil). As a result, the large-scale fluid-solid coupling simulation also put forward higher requirements. At the same time, with the emergence of massive simulation data, how to carry out efficient and reasonable post-processing and visualize it in a efficient way has become an urgent problem to be solved in large-scale geotechnical simulation. Aiming at the above two problems: large-scale geotechnical fluid-solid coupling simulation and large-scale visualization, the paper makes some explorations and researches. First, the research develops the liquefaction large deformation constitutive model and improve solution modules based on the existing platform GEOSX. Besides, the research develops the corresponding visualization solutions based on Unity3D engine. The main achievements and conclusions of this paper include: (1) Based on the high-performance numerical simulation platform GEOSX developed by LLNL, the research develops CycLiqCPSP constitutive model module and other solution modules, including different material partition solution, tied velocity boundary condition, pore pressure boundary condition and other modules. Based on the above development, GEOSX can realize large-scale dynamic fluid-solid coupling simulation based on CycLiqCPSP model. The validity and rationality of the fluid-solid coupling simulation of CycLiqCPSP model is proved, through the triaxial drained and undrained tests, one-dimensional soil column dynamic response test and two-dimensional soil dynamic response test. (2) Based on Unity3D engine, a large-scale simulation visualization software GIV for geotechnical engineering is developed in this paper, which can be used to process the massive data generated by large-scale simulation of geotechnical engineering. In GIV, the pre-processing module can effectively compress large-scale simulation data and provide the possibility for the lightweight of visualization. Besides, the visualization module optimizes the data access mode and user interaction, improving the efficiency of visualization and the friendliness of interaction. Through a series of tests of benchmark models and practical model, the effectiveness of GIV in dealing with large-scale geotechnical simulation visualization is proved. (3) The above schemes of large-scale simulation and visualization are applied to simulation and post-processing of free field and underground engineering. In the application research, the validity and rationality of the above large-scale dynamic fluid-solid coupling scheme are verified again by the analysis of the deformation and stress-strain of the models. Besides, the efficiency and convenience of the above visualization scheme of large-scale geotechnical simulation visualization are proved by the preprocessing analysis and the visualization performance. In conclusion, this study proposes a set of solutions from simulation to visualization for large-scale geotechnical dynamic fluid-solid coupling simulation and prove their verify.
