裂隙刚度随应力变化对双重孔隙介质热-水-应力耦合影响的有限元分析  

Finite element analysis of influence of fracture stiffness changing with stress on thermo-hydro-mechanical coupling in dual-porosity medium

作　　者：张玉军[1] 徐刚[1] 杨朝帅[1] 

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

出　　处：《岩土力学》2012年第11期3426-3432,共7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：引入并修正了变刚度的连续屈服节理模型,同时考虑应力拉压和压力(化学)溶解对裂隙开度的综合影响,对所建立的双重孔隙-裂隙介质热-水-应力耦合有限元计算程序作了改进。通过一个假定的高放废物地质处置库的数值模拟,就岩体裂隙刚度变化的2种工况,分析了岩体中的温度、裂隙刚度、正应力、孔(裂)隙水压力和地下水流速的变化、分布情况。结果显示:与裂隙刚度是常数时相比,裂隙刚度是法向应力的函数时计算域中温度较低;岩体应力的大小也有一定不同,其分布与裂隙刚度"场"有明显的相似性;并且负孔(裂)隙水压力的绝对值要略小一点,约是常数时的98%。Introducing and modifying the continuously yielding joint model,and simultaneously considering the composite impact of mechanical dilation/compaction and pressure solution on fracture aperture,the FEM code for analysis of the thermo-hydro-mechanical coupling in dual-porosity medium established by the first author was improved.Through the numerical simulations in which there were two patterns of changing the fracture stiffness for a hypothetical nuclear waste repository,the variations and distributions of temperatures,fracture stiffnesses,normal stresses,pore（fracture） pressures,flow velocities of groundwater were investigated.The results show： compared with the case of unchangeable fracture stiffness,the temperatures in the computing domain are lower in the case whose fracture stiffness is an exponential function of normal stress;the magnitudes of stresses within the rock mass in two cases are also some different,but the characteristics of stress distribution are similar to those of fracture stiffnesses obviously;and the negative pore（fracture） pressures in the case with changeable fracture stiffness are smallish（about 98% of case of unchangeable fracture stiffness）.

关 键 词：双重孔隙介质 连续屈服节理模型 热-水-应力耦合 有限元分析 

分 类 号：O242[理学—计算数学]