贯通单裂隙北山花岗岩水-力耦合特性研究  

Study on hydro-mechanical characteristics of Beishan granite with single through-fracture

作　　者：王锡勇[1,2] 李炜强 WANG Xiyong;LI Weiqiang(Beijing Research Institute of Uranium Geology,Beijing 100029,China;CAEA Innovation Center for Geological Disposal of High-Level Radioactive Waste,Beijing 100029,China)

机构地区：[1]核工业北京地质研究院,北京100029 [2]中国国家原子能机构高放废物地质处置创新中心,北京100029

出　　处：《世界核地质科学》2024年第5期988-996,共9页World Nuclear Geoscience

基　　金：中国国家原子能机构核设施退役及放射性废物治理项目(编号:科工二司[2020]194号)资助。

摘　　要：为研究裂隙花岗岩的水-力耦合特性及其变形破坏过程中渗透特性的演化特征,以含倾角30°、45°和60°贯通单裂隙的花岗岩为研究对象,开展三轴压缩试验、围压分级加载的渗透试验以及三轴压缩耦合渗透测试的水-力耦合试验。结果表明:裂隙花岗岩的渗透系数随围压的增大而有所降低,随轴向应变的增大呈现出先降低后增大最后再降低的趋势。0.5 MPa渗透压差的水-力耦合条件会导致倾角30°、45°和60°裂隙花岗岩的抗压强度分别下降11.75%、25.42%和21.52%,弹性模量分别下降28.64%、40.15%和27.35%,但不会对其破坏形式造成显著影响。裂隙花岗岩的破坏形式分别为:穿裂隙面破坏(30°)、穿裂隙面破坏和沿裂隙面滑移并存的复合破坏(45°)以及沿裂隙面滑移破坏(60°)。To investigate the hydro-mechanical characteristics of fractured granite and the evolution properties of permeability during its deformation and failure process,a series of laboratory experiments were conducted on granite specimens with single through-fractures with dip angles of 30°,45°and 60°,including triaxial compression test,permeability test with graded confining pressures,as well as hydro-mechanical coupling test of triaxial compression test coupled with permeability test.The results indicate that the permeability coefficient of fractured granite decreases with increasing confining pressure.With the increasing axial strain,the permeability coefficient also shows a trend of initially decreasing,then increasing,and finally decreasing again.Under the hydro-mechanical coupling conditions of a osmotic pressure difference of 0.5 MPa,the compressive strength of granite with fracture dipped at 30°,45°and 60°decreases by 11.75%,25.42%,and 21.52%,respectively,and the elastic modulus decreases by 28.64%,40.15%and 27.35%,respectively.However,the hydro-mechanical coupling condition does not significantly affect the type of failure.The failure modes of fractured granite are as follows:new cracks propagate through pre-existing fracture surfaces(30°),sliding along the pre-existing fracture surfaces(60°),and compound failure with coupled damages of the previous two types.

关 键 词：裂隙倾角 渗透系数 破坏形式 北山花岗岩 

分 类 号：TU443[建筑科学—岩土工程]