存在边界流时压力溶解对颗粒聚集岩体中THM耦合作用的有限元模拟  

FEM simulation for influences of pressure solution on THM coupling in aggregate rock under boundary influx

作　　者：张玉军[1] 杨朝帅[1,2] 

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,湖北武汉430071 [2]中国中铁隧道集团有限公司技术中心,河南洛阳471009

出　　处：《中南大学学报（自然科学版）》2013年第12期5100-5108,共9页Journal of Central South University:Science and Technology

基　　金：国家重点基础研究发展计划("973"计划)资助项目(2010CB732101);国家自然科学基金资助项目(51079145;51379201)

摘　　要：在孔隙介质热-水-应力耦合有限元程序中引入颗粒聚集体的压力溶解模型,针对一个假设的实验室尺度且位于饱和石英颗粒聚集岩体中的高放废物地质处置库,拟定2种计算工况即边界上水压力相同(工况1)和左、右边界上水压力有较大的差别(工况2),进行4 a处置时段的数值模拟,考察岩体中的温度、颗粒界面水膜及孔隙中的溶质浓度、迁移和沉淀质量、孔隙率及渗透系数、孔隙水压力、地下水流速和应力的变化、分布情况。研究结果表明:与工况1相比,工况2的计算域中有较大的地下水流速(稳态流量Qss),可促进颗粒介质的溶解、迁移和沉淀,使得孔隙率和渗透系数加快下降,从而对渗流场(孔隙水的压力及流速)和应力场产生显著的影响。The model of pressure solution for granular aggregates established by Taron et al was introduced into the FEM （finite element method） code for analysis of THM （thermo-hydro-mechanical） coupling in porous media. Aiming at a hypothetical nuclear waste repository in a saturated quartz aggregate rock mass with a laboratory scale, two computation cases were designed： the pore pressures at all boundaries are the same （Case 1）; a larger difference between the pore pressures at left boundary and right boundary exists （Case 2）. Then the corresponding numerical simulations for a disposal period of 4 years were carried out, and the states of temperatures, solute concentrations in the intergranular fluid film and at the pore space, removal and precipitation masses, porosities and permeabilities, pore pressures, flow velocities and stresses in the rock mass were investigated. The results show that, compared with Case 1, there are larger flow velocities of underground water （steady state influx Qss） in the computation domain of Case 2, which promotes solution, diffusion and precipitation of the granular medium, so the porosities and permeabilities of aggregate rock mass decrease quickly, which produces obvious effects on the seepage field（pressures and flow velocities of pore water） and the stress field.

关 键 词：压力溶解 颗粒聚集岩体 边界流 热-水-应力耦合 有限元模拟 

分 类 号：O354[理学—流体力学]