基于时域显式数值算法的饱和冻土地震响应研究

Study on the Seismic Response of Saturated Frozen Soil Based on an Explicit Numerical Algorithm in Time-Domain

摘要: 将饱和冻土模拟为含孔隙固体三相多孔介质(PSPM)，基于Carcione-Leclaire波动方程描述其波动特性，应用时域显式数值算法，并结合透射人工边界条件，进行了饱和冻土自由场地震响应的计算研究。计算结果符合弹性波动理论的规律，表明了时域显式数值算法对于饱和冻土近场波动问题的适用性。计算结果同时表明，在输入地震动作用下，饱和冻土中的固体骨架、孔隙流体和孔隙固体的地震响应幅值基本一致，表明饱和冻土中的三相物质成分在动力荷载作用下具有协同变形特征，呈现出动力协调性。

Abstract: Saturated frozen soil was modeled as the porous media containing pore-solid (PSPM), and its wave characteristics were governed by the Carcione-Leclaire wave propagation equation. A time-domain explicit numerical algorithm was adopted. It was combined with a transmissive artificial boundary condition. Using this approach, a computational study was conducted on the free-field seismic response of saturated frozen soil. The computational results are consistent with the principles of elastic wave theory. Therefore, the applicability of the explicit time-domain numerical algorithm to near-field wave problems in saturated frozen soil is demonstrated. The results also indicate that, under the action of input seismic motion, the seismic response amplitudes of the solid skeleton, pore-fluid, and pore-solid in saturated frozen soil are essentially consistent. This suggests that the three-phase components in saturated frozen soil exhibit cooperative deformation characteristics under dynamic loading. Thus, dynamic coordination is demonstrated.