A decoupled ALE method is developed based on operator splitting technique and soil water two-phase mixture theory and applied to the seismic response analysis of subway station in saturated sand in this research. It is found that the Rayleigh damping coefficients have a remarkable influence on the deformation shape, the final floating, and the acceleration response of the underground structure, which needed to fully consider the influence factors to avoid over-damping or under-damping of the system. The comparison of the seismic response of the subway station from the UL method and the proposed ALE method verifies the applicability of the method for such problems. Additionally, the ALE method is utilized to the seismic response of the subway station in deep loosed sand in the case of mesh distortion in the UL method. The results show that the ALE method ensures the mesh quality and the solution accuracy of the model. Owing to the subway station uplift, the ground near the subway station uplifts, while settles far away from the station, and the higher the earthquake intensity, the wider the range of the ground affected to uplift. The development of excess pore pressure ratio in the soil is synchronous with the corresponding Arias intensity. The uplift of the subway station could be divided into initial floating stage and fast floating stage, and the excess pore pressure ratio triggering the structure into initial floating stage and fast floating stage falls in a range rather than a threshold, except for the complete liquefaction site. The liquefied sand flows to the beneath of the subway station is the primary factor causing the structure to uplift. Moreover, the Ratcheting mechanism, Pore pressure migration mechanism, and the Viscous flow mechanism all contribute to the subway station floating. It is found that the increase of the buried depth will approximately linearly decrease the floating of the subway station, the vertical excitation has little effect on the floating of underground structure, while the densification of soil on both sides and beneath the subway station can significantly decrease the floating rate and floating of the subway station.

本研究基于算子分裂技术和土水两相混合理论，开发了一种解耦ALE方法，并将其应用于饱和砂土中地铁车站的地震响应分析。研究发现，瑞利阻尼系数对地下结构的变形形状、最终漂浮和加速度响应有显着影响，需要充分考虑影响因素，避免系统过阻尼或欠阻尼. UL 方法和提出的 ALE 方法对地铁站地震响应的比较验证了该方法对此类问题的适用性。此外，在UL方法中，在网格畸变的情况下，ALE方法被用于深松沙中地铁站的地震响应。结果表明，ALE方法保证了模型的网格质量和求解精度。由于地铁站隆升，地铁站附近的地面隆升，而远离车站的地面沉降，地震烈度越高，受隆起影响的地面范围越广。土壤中超孔隙压比的发展与相应的阿里亚斯强度同步。地铁站的抬升可分为初浮阶段和快浮阶段，除完全液化现场外，引发结构进入初浮阶段和快浮阶段的超孔隙压比落在一个范围内，而不是一个阈值范围内。 . 液化砂流向地铁站下方是导致结构抬升的主要因素。而且，棘轮机制、孔隙压力迁移机制和粘滞流机制都有助于地铁站的漂浮。研究发现，随着埋深的增加，地铁站的浮力近似线性降低，竖向激励对地下结构的浮力影响不大，而地铁站两侧和下方土壤的致密化程度显着降低。地铁站的浮动费率和浮动。