考虑裂隙的几何-力学特性的双重孔隙介质水-应力耦合模型及其有限元分析

建立了一种双重孔隙介质水-应力耦合模型,其特点是可考虑裂隙的组数、间距、方向、连通率、开度、刚度及应力水平对介质的弹性模量、孔隙率及渗透系数的影响,并研制出相应的二维有限元程序.以模拟饱和的双重孔隙岩体在外荷载作用下产生沉降为算例,针对岩体的孔隙率与渗透系数分别是常数及按照本文中所述规律变化的两种工况,考察了不同岩体中的变形、孔隙水压力与裂隙水压力及流速、主应力等的分布与变化.结果表明:将岩体的孔隙率与渗透系数作为应力的函数,与将其作为常量的方法相比,二者对岩体的变形及应力的影响不大,但前者对孔隙水压力、裂隙水压力及流速的影响强烈.

Coupled hydro-mechanical model and FEM analyses for dual-porosity media considering geometric-mechanical characteristics of fractures

A kind of coupled hydro-mechanical model for dual-porosity media was established, in which the influences of sets, spaces, angles, continuity ratios, apertures, stiffnesses of the fractures and the stress levels on the elastic modulus, porosities and permeabilities of the media can be considered, and also the relative two-dimensional program of finite element method was developed. Taking the settlement process of a saturated dual-porosity rockmass loaded as a calculation example, two cases were simulated numerically in which the porosities and permeabilities of the rockmass are constants and variables respectively, and the displacements, pore pressures, fracture pressures, flow velocities and principal stresses in the rockmass were investigated. The results show that using the unchangeable porosities and permeabilities and taking them as the functions of stress have no obvious effect on the deformations and stresses in the rocknass, but compared with the former, the latter impacts upon intensively the pore pressures, fracture pressures and flow velocities.