裂隙花岗岩力学特性试验及破坏条件理论模型  

Experimental Study of Mechanical Properties and Theoretical Model of Failure Conditions for Fractured Granite

作　　者：黄勇钧 李世文 刘先林 邵羽 翁剑 任中俊[5] 吕玺琳[4] HUANG Yongjun;LI Shiwen;LIU Xianlin;SHAO Yu;WENG Jian;REN Zhongjun;LU Xilin(Guangxi New Development Transportation Group Co.Ltd.,Nanning 530029,Guangxi,China;Guangxi Lewang Expressway Co.Ltd.,Nanning 530029,Guangxi,China;Guangxi Communications Design Group Co.Ltd.,Nanning 530029,Guangxi,China;Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China;Hunan Provincial Key Laboratory of Geotechnical Engineering for Stability Control and Health Monitoring,Hunan University ofScience and Technology,Xiangtan 411201,Hunan,China)

机构地区：[1]广西新发展交通集团有限公司,广西南宁530029 [2]广西乐望高速公路有限公司,广西南宁530029 [3]广西交通设计集团有限公司,广西南宁530029 [4]同济大学岩土及地下工程教育部重点实验室,上海200092 [5]湖南科技大学岩土工程稳定控制与健康监测湖南省重点实验室,湖南湘潭411201

出　　处：《力学季刊》2025年第1期162-172,共11页Chinese Quarterly of Mechanics

基　　金：广西重点研发计划项目(AB22080024);广西南宁市“邕江计划”青年人才专项项目(RC20230108);广西交通运输科技成果推广项目(GXJT-CXLHT-2023-02-01)。

摘　　要：花岗岩内部常含初始裂隙,导致其强度特性受裂纹扩展影响较大.当前的岩石强度理论尚未考虑裂纹扩展,难以有效反映裂隙花岗岩的强度和破坏特性.针对完整和裂隙花岗岩开展了单/三轴压缩试验和巴西劈裂试验,研究了拉伸及压缩条件下的强度与破坏特性,探讨了围压和裂隙倾角(裂隙与横断面夹角)对花岗岩刚度、强度及破坏模式的影响规律,并提出一种能反映裂纹扩展的岩石强度计算方法.根据完整花岗岩发生Ⅱ型裂纹摩擦滑移、裂隙花岗岩发生Ⅰ-Ⅱ型复合断裂的特点,基于断裂力学理论建立了完整和裂隙花岗岩的破坏条件.理论分析结果表明,初始裂隙会显著降低花岗岩的抗压强度和变形刚度,其抗压强度、弹性模量及割线模量均随裂隙倾角减小而降低,而泊松比则增大.初始裂隙会明显降低花岗岩的抗拉强度,且抗拉强度随裂隙倾角减小而降低.Granite often contains initial cracks,therefore its strength characteristics are greatly affected by crack propagation.Most of the existing rock strength theories do not consider crack propagation,making them difficult to effectively reflect the strength and failure characteristics of the fractured granite.In this paper,uniaxial/triaxial compression tests and Brazilian splitting tests were conducted on the intact and fractured granite samples to study the strength and failure characteristics under tensile and compression conditions.The influences of confining pressure and crack inclination angle(the angle between the crack and the cross-section plane)on the strength stiffness and failure mode of granite were analyzed,and a method for calculating the strength of the initially cracked rocks was proposed.Based on the propensities of type Ⅱ friction slip fracture in intact granite and type Ⅰ-Ⅱ composite fracture in fractured granite,the failure conditions of intact and fractured granite were established according to fracture mechanics theory.The experimental results show that the compressive strength and stiffness of granite specimens are significantly reduced by the introduction of initial crack.The compressive strength,elastic modulus,and secant modulus decrease with the crack inclination angle,while Poisson's ratio shows opposite trend.The initial cracks will significantly reduce the tensile strength of granite,which decreases with the decrease of crack inclination angle.

关 键 词：花岗岩 初始裂隙 压缩与劈裂试验 强度特性 破坏条件 

分 类 号：TU458.3[建筑科学—岩土工程]