饱和砂土流固耦合细观数值模型及其在液化分析中的应用

Fluid-particle coupled model for saturated sand and its application to liquefaction analysis

在饱和砂土连续力学模型的基础上,建立了一个饱和砂土固相颗粒和液相流体耦合的细观力学模型,固相颗粒采用离散元的颗粒流理论模拟,液相流体通过求解平均Navier-stokes方程的计算流体动力学技术计算。该细观模型用二维渗流问题进行了验证,并将其应用于饱和砂土的液化分析。数值模拟结果显示,采用的模型可以描述从低雷诺流到高雷诺流范围很大的流体运动。液化分析表明:液化首先在试样的表层产生,接着向深部发展;而超孔隙水压力则从底部开始消散,然后逐渐向上发展,直至完全消散。砂土液化过程中土体孔隙率不断变化,渗透系数也随之改变。

Based on the continuum model for analysis of saturated porous media,a fluid-particle coupled model was established to simulate the meso-scale pore water flow and micro-scale solid deformation of saturated soils.The particles were simulated by discrete element method,while the fluid flow was simulated by solving the average Navier-Stokes equations.The validity of this model was verified by a two-dimension flow case study and the model was applied to analyze the liquefaction phenomena of saturated sand.The nu...