基于改进刚体弹簧方法的岩石破坏过程三维模拟  

Three-dimensional numerical simulation of rock failure process based on the modified rigid-body-spring method

作　　者：何忱 姚池[1] 姜清辉[2] 周创兵 HE Chen;YAO Chi;JIANG Qinghui;ZHOU Chuangbing(School of Infrastructure Engineering,Nanchang University,Nanchang,Jiangxi 330031,China;School of Civil Engineering,Wuhan University,Wuhan,Hubei 430072,China)

机构地区：[1]南昌大学工程建设学院,江西南昌330031 [2]武汉大学土木建筑工程学院,湖北武汉430072

出　　处：《岩石力学与工程学报》2023年第1期183-193,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(52079062,52004127);江西省自然科学基金项目(20204BCJ23002)。

摘　　要：基于刚体-弹簧方法,提出一种新的模拟脆性岩石破坏过程的三维离散数值模型。该模型采用分布在界面上的弹簧组,描述块体之间的相互作用,能够自然考虑裂纹的渐进扩展。为得到均质各向同性的计算网格,在“点饱和”方法的基础上,提出了增长式的“核”布置策略,建立一种新的随机Voronoi网格剖分技术,并给出三维改进刚体–弹簧方法的基本方程。考虑界面的剪切滑移和张拉2种破坏模式,建立基于Mohr-Coulomb准则和抗拉强度准则的破坏准则,并提供模型细观参数的标定流程。最后,通过与室内三轴试验结果对比,验证了该模型的有效性。此外,还讨论了不同弹簧布置形式及块体尺寸对模拟结果的影响。结果表明,所提模型能够准确描述岩石与围压相关的非线性应力–应变响应过程,微裂纹的产生、扩展和贯通全过程,以及岩石的在不同围压条件下的宏观破坏模式。Based on the rigid-body-spring method,a new three-dimensional discrete numerical model is proposed to simulate the progressive failure process of brittle rocks.The model describes the interaction between rigid blocks by means of spring-set groups distributed on the interface of blocks.Thus,the progressive crack propagation is naturally considered.To obtain a basic mesh with high homogeneous and isotropic crack direction,a new random Voronoi mesh technology with a growth“nucleus”place strategy is proposed based on the“point saturation”strategy.Then,the basic functions of three-dimensional modified rigid-body-spring method are proposed.Considering mesoscopic shear and tensile failure modes,a failure criterion based on Mohr-Coulomb criterion with maximum tensile strength is established,and the calibration strategy of mesoscopic parameters of the new model is provided.Finally,the proposed model is validated by comparing with the results of laboratory triaxial tests.Effects of the pattern of the spring-sets configuration and the block size on the simulation results are also discussed.The results show that the proposed model can correctly describe non-linear stress-strain responses,evolution of micro-cracks,and macroscopic failure mode of the rocks under different confining pressures.

关 键 词：岩石力学 刚体弹簧方法 Voronoi网格 岩石破裂 离散单元法 围压效应 

分 类 号：TU45[建筑科学—岩土工程]