考虑饱和度修正的应力腐蚀和压力溶解作用热-水-应力耦合过程有限元分析  

Finite element analysis of thermo-hydro-mechanical coupling processes under stress corrosion and pressure solution considering saturation correction

作　　者：张维庆 张玉军[2] 

机构地区：[1]中铁隧道勘测设计院有限公司,天津300133 [2]中国科学院武汉岩土力学研究所 岩土力学与工程国家重点实验室,武汉430071

出　　处：《岩土力学》2013年第S1期523-532,共10页Rock and Soil Mechanics

基　　金：国家重点基础研究发展计划(973)项目资助(No.2010CB732101);国家自然科学基金资助(No.51079145)

摘　　要：针对笔者开发的双重孔隙-裂隙介质热-水-应力(T-H-M)耦合二维有限元分析程序中使用的应力腐蚀和压力溶解模型,引入水饱和度修正因子。以一个假设的位于含水地层中的高放废物地质处置模型,拟定3种初始裂隙水饱和度的计算工况(Sw20=1.0、0.8、0.2)进行热-水-应力耦合的数值模拟,考察岩体中的温度、裂隙开度的闭合速率、闭合量、孔(裂)隙水压力、地下水流速和应力的变化、分布等情况。结果显示,随着初始裂隙水饱和度的由高值到低值,应力腐蚀和压力溶解产生的闭合速率从大变小,裂隙开度由初始值趋于残余值,粗糙面接触率由初始值趋于其名义接触率的时间也增加,裂纹应力强度因子的下降亦变慢;近场的裂(孔)隙水压力的变化、分布及其流速矢量场的形态有明显的不同;3种工况的岩体中的应力量值及分布的差别不大。For the models of stress corrosion and pressure solution used in the 2D finite element method(FEM) code of thermo-hydro-mechanical coupling analysis for dual-porosity medium developed by the authors,a correction factor for water saturation is introduced.Aiming at a hypothetical model for geological disposal of nuclear waste located at a water-bearing stratum,three computation conditions with different initial fracture saturations were designed(Sw20 =1.0、0.8、0.2),then the corresponding two-dimensional numerical simulation for the coupled thermo-hydro-mechanical processes were carried out;and the states of temperatures,rates and magnitudes of aperture closure,pore and fracture pressures,flow velocities and stresses in the rock mass were investigated.The results show:With the change of initial fracture saturation from high value to low value,the closure rates caused by stress corrosion and pressure solution vary from fast to slow,and the times of fracture aperture tending to its residual value and contact-area ratio of asperity tending to its nominal area from their initial values also increase,as well as the drop in stress intensity factors slows down;the changes and distributions of fracture and pore pressures in near-field as well as the states of flow vectors have obvious distinctions;the magnitudes and distributions of stresses within the rock mass in three calculation cases make little difference.

关 键 词：应力腐蚀 压力溶解 饱和度修正 双重介质 热-水-应力(T-H-M)耦合 有限元分析 

分 类 号：O241.82[理学—计算数学]