Abstract

We present a strong nonlocal hydromechanical model formulated based on state-based peridynamics for simulating strain localisation in unsaturated geomaterials. The governing equations are integro-differential equations in which length scales are assumed for both the skeleton deformation and pore fluid flow. Recently proposed hydromechanical correspondence principle is adopted to implement the classical local constitutive model for the solid skeleton, and the generalised Darcy’s law for unsaturated water flow into the nonlocal hydromechanical model. Numerical simulations of shear bands in unsaturated geomaterials were conducted to investigate the effect of the hydromechanical length scale and the mechanical loading rate on the formation of shear bands. The numerical results have shown that both the deformation and pore water pressure are concentrated in the shear bands with a finite thickness. The numerical results have demonstrated that both the hydromechanical length scale and the mechanical loading rate affect the formation of shear bands in unsaturated geomaterials and the peak value of the load capacity of unsaturated geomaterials.

摘要

我们提出了一个基于基于状态的近场动力学制定的强大的非局部流体力学模型，用于模拟不饱和地质材料中的应变局部化。控制方程是积分微分方程，其中假定骨架变形和孔隙流体流动的长度尺度。采用最近提出的流体力学对应原理，将经典的实体骨架局部本构模型，将非饱和水流的广义达西定律引入到非局部流体力学模型中。对非饱和土工材料中的剪切带进行了数值模拟，研究了流体力学长度尺度和机械加载速率对剪切带形成的影响。数值结果表明，变形和孔隙水压力都集中在有限厚度的剪切带中。数值结果表明，流体力学长度尺度和力学加载速率均影响非饱和土工材料剪切带的形成和非饱和土工材料承载能力的峰值。