岩石压缩破坏强度的一种理论估值方法  

A theoretical approach to estimation of the rock failure strength under complex compression

作　　者：林大超[1] 徐谦 王仲琦[2] 刘海波[1] LIN Dachao;XU Qian;WANG Zhongqi;LIU Haibo(Department of Civil Engineering,North China Institute of Science and Technology,Sanhe,Hebei 065201,China;State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]华北科技学院土木工程系,河北三河065201 [2]北京理工大学爆炸科学与技术国家重点实验室,北京100081

出　　处：《岩石力学与工程学报》2021年第S01期2603-2612,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家科技重大专项(2016ZX05006-002)。

摘　　要：依据简单加载试验结果可靠地预测复杂载荷条件下岩石的破坏强度仍是一项挑战性任务。以Mohr-Coulomb准则力学模型的能量描述为基础,提出一种应用单轴压缩试验估值岩石压缩破坏强度的理论方法。包括由破坏面上一点弹性变形能与裂纹表面能守恒关系给出的压缩破坏临界能量条件,以及在常剪切弹性模量和体积变化服从体积应力幂指数律条件下,从临界能量条件导出的岩石真三轴压缩破坏强度判据。不同于已提出的各种岩石破坏准则,这个判据考虑到了岩石的变形和开裂特征。3个材料参数不由强度试验数据的拟合确定,而是单轴压缩试验信息的计算结果。应用实例分析表明,它的强度预测结果达到了Hoek-Brown经验强度准则关于试验数据最优拟合的精度水平。There is still a challenge to reliably predict failure strengths of a rock subjected to complex loads by means of its experimental results under simple loading conditions.This work,based on the energy description of the mechanical model of Mohr-Coulomb criterion,suggests an approach to theoretically estimating the failure strength of the rock under complex compression from uniaxial compression test.It includes a critical energy condition for failure that is resulted from the energy conservation law between the elastic strain energy and the surface energy of crack at a point on the failure surface,and a failure criterion of the rock under polyaxial compression that is derived from the critical energy condition under the condition of constant shear modulus of elasticity and the volume change following a power law of the volumetric stress.Different from previously developed rock failure criteria,this criterion takes characteriscs of the rock deformation and cracking into account.Instead of being determined by fitting the test data of strengths,its three parameters are determined in calculation by using information of the uniaxial compression test.Applications show that the accuracy of its strength prediction may reach the same level as the best-fitting solution by using the Hoek-Brown empirical failure criterion.

关 键 词：岩石力学 岩石强度 破坏准则 三轴压缩 真三轴压缩 临界能量条件 强度预测 

分 类 号：TU45[建筑科学—岩土工程]