核废物地质处置中热-水-应力耦合对迁移影响的三维有限元模拟  

3D finite element simulation for influence of thermo-hydro-mechanical coupling on migration in geological disposal of nuclear waste

作　　者：张玉军[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》2009年第7期2126-2132,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No50578171)

摘　　要：将所建立的热-水-应力-迁移耦合模型及开发的有限元程序,由二维分析拓展到三维分析,并从方法论研究的角度,以一个简单的核废物地质处置模型为算例,进行热-水-应力-迁移耦合过程的三维数值模拟,考察了近场的温度、饱和度、核素浓度、孔隙水压力、位移、正应力、流速等的分布与变化,认为计算结果符合规律,得出了若干结论:为了精确地模拟放射性核素迁移,就必须将温度场、渗流场、应力场和核素浓度场进行耦合分析;核废物埋存若干年后将在处置孔壁附近产生较高的压应力;缓冲层内各点的核素浓度达到相对稳定的时间要比温度和饱和度达到相对稳定的时间长得多。A 2D model for coupling thermo-hydro-mechanical-migration and the relevant FEM code made by author is extended to 3D. From the viewpoint of methodology study, a 3D numerical simulation for the coupled thermo-hydro-mechanical-migratory processes in a simple model of geological disposal of nuclear waste, which is taken for example, is carried out. The distributions and changes of the temperature, saturation, nuclide concentration, pore pressure, displacement, normal stress and flow velocity in the near field are investigated. It is considered that the computation results are in keeping with the regular pattern. Finally, some conclusions are drawn.- in order to simulate the migration of radioactive nuclide accurately, it is necessary to analyze temperature field, seepage field, stress field and nuclide concentration field by coupled method; higher compressive stresses will appear in the neighborhood of disposal pit wall after several decades from the embedment of nuclear waste; in buffer layer the period during which nuclide concentration reaches relative stabilization is much longer than those during which temperature and saturation reach relative stabilization respectively.

关 键 词：岩石力学 核废物 地质处置 热-水-应力-迁移耦合 三维模型 有限元分析 

分 类 号：TU45[建筑科学—岩土工程] O242[建筑科学—土工工程]