应力腐蚀和压力溶解引起的裂隙开度-刚度变化对THMM耦合过程影响的数值模拟  

Numerical simulation for influence of fracture aperture-stiffness change caused by stress corrosion and pressure solution on T-H-M-M coupling processes

作　　者：张玉军[1] 徐刚[1] 杨朝帅[2] 

机构地区：[1]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 [2]中铁隧道集团有限公司技术中心,河南洛阳471009

出　　处：《岩土力学》2013年第2期559-567,共9页Rock and Soil Mechanics

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

摘　　要：在使用Yasuhara等建立的裂隙开度的应力腐蚀和压力溶解模型的基础上,考虑裂隙闭合量对裂隙刚度的影响,针对一个假设的位于非饱和双重孔隙-裂隙岩体中且有核素泄漏的高放废物地质处置模型,拟定两种计算工况:(1)裂隙的刚度系数是裂隙闭合量的线性函数;(2)裂隙刚度为常数,进行热-水-应力-迁移耦合的二维有限元数值模拟,考察了岩体中的温度、裂隙开度的闭合速率、闭合量、孔(裂)隙水压力、地下水流速、核素浓度、裂隙刚度和正应力的变化、分布等情况。结果表明,两种工况岩体中的温度场、孔(裂)隙水压力、地下水流速、核素浓度无明显差别;裂隙闭合基本由应力腐蚀产生;在相同计算时间内两种工况的裂隙闭合量较为接近,工况1略大;工况1中离玻璃固化体越近,裂隙刚度值越高,并且在玻璃固化体附近的应力值较大,且集中程度较高。On the basis of using the models of stress corrosion and pressure solution established by Yasuhara et al,the effect of fracture aperture closure on the fracture stiffnesses is considered.Aiming at a hypothetical model for geological disposal of nuclear waste in an unsaturated dual-porosity-fractured rock mass from which there is a nuclide leak,two computational conditions are designed：（1） the stiffness coefficients of a fracture are linear functions of magnitude of fracture aperture closure;（2） the stiffness coefficients of a fracture are constants,then the corresponding two-dimensional numerical simulations for the coupled thermo-hydro-mechanical-migratory processes are carried out by using finite element method;and the states of temperatures,rates and magnitudes of fracture aperture closure,pore and fracture pressures,flow velocities of underground water,nuclide concentrations,fracture stiffnesses and normal stresses in the rock masses are investigated.The results show： there are no obvious differences between the temperature fields,pore and fracture pressures,flow velocities of underground water,nuclide concentrations in the rock masses of two cases;fracture aperture closure is produced mainly by stress corrosion;the magnitudes of fracture aperture closure in two cases are closer each other at the same computation time;and those of case 1 are slightly larger;in the rock mass of case 1,the nearer the vitrified waste is,the higher the fracture stiffnesses are;and the larger stress values and higher stress concentrations occur in the vicinity of the vitrified waste.

关 键 词：应力腐蚀 压力溶解 双重孔隙-裂隙介质 裂隙刚度 热-水-应力-迁移耦合分析 

分 类 号：O241[理学—计算数学]