摘要
含裂隙围岩的力学行为对高放废物地质处置库的长期稳定和安全至关重要。为研究围压和裂隙倾角对花岗岩围岩力学行为的影响,以完整花岗岩和含不同倾角贯通单裂隙的花岗岩为研究对象,开展了单轴压缩和三轴压缩试验研究。结果表明:0~10 MPa围压范围内,倾角30°和60°裂隙花岗岩分别发生了穿裂隙面破坏和沿裂隙面滑移破坏;随围压升高,倾角45°裂隙花岗岩由复合破坏转变为穿裂隙面破坏,后又在10 MPa围压条件下再次转变为倾斜“Z”字型裂纹的复合破坏。围压的存在制约了预制裂隙面的劣化作用。三轴压缩条件下低倾角裂隙花岗岩的抗压强度及变形发展曲线与完整花岗岩的结果相近,试样峰值破坏时的轴向应变在围压0,2,5,10MPa条件下分别约为0.38%,0.49%,0.59%和0.75%。沿裂隙面滑移破坏试样的抗压强度以及峰值破坏时的轴向应变均显著低于穿裂隙面破坏试样的相关结果,且其抗压强度与试验前后裂隙面的分形维数差值符合幂函数增长关系。
The mechanical behavior of host rock with fractures is crucial for the long-term stability and safety of a high-level radioactive waste geological disposal facility.To investigate the influences of confining pressure and fracture inclination on the mechanical behavior of granite host rock,the uniaxial compression and triaxial compression tests are conducted on the intact granite and granite with single fractures of different inclinations.The results show that within the confining pressure range of 0~10 MPa,the granite with fractures inclined at 30°and 60°experiences the failure of newly formed cracks that penetrate through the pre-existing fracture surfaces and the slip failure along the fracture surface,respectively.As the confining pressure increases,the granite with fractures inclined at 45°undergoes a transition from composite failure to failure through the fracture surfaces.It then transits back to a tilted"Z"-shaped composite failure under a confining pressure of 10 MPa.The presence of confining pressure constrains the deterioration of pre-existing fracture surfaces.The compressive strength and deformation development curves of low-angle fractured granite under triaxial compression conditions are similar to those of the intact granite,and the axial strains at the peak failure of these specimens are approximately 0.38%,0.49%,0.59%and 0.75%under confining pressures of 0,2,5,and 10 MPa,respectively.The compressive strength and axial strain at peak failure of specimens that experience slip failure are significantly lower than those of specimens that experience failure through the fracture surface,and the compressive strength shows a power-law relationship with the difference in fractal dimensions between the fracture surfaces before and after the tests.
作者
王春萍
刘建锋
刘健
王璐
薛福军
WANG Chunping;LIU Jianfeng;LIU Jian;WANG Lu;XUE Fujun(Beijing Research Institute of Uranium Geology,Beijing 100029,China;CAEA Innovation Center for Geological Disposal of High-Level Radioactive Waste,Beijing 100029,China;College of Water Resource&Hydropower,Sichuan University,Chengdu 610065,China;School of Architecture and Civil Engineering,Xihua University,Chengdu 610039,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2024年第3期578-586,共9页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(42307258)
核设施退役治理专项资助科研项目(科工二司[2020]194号)
四川省科技攻关项目(2023ZYD0154,2024JHZ0035)。
关键词
北山花岗岩
裂隙
三轴压缩
破坏形式
高放废物地质处置
Beishan granite
fracture
triaxial compression
failure form
high-level radioactive waste geological disposal
