不同节理模型在层状复合岩石离散元模拟中的应用  

Application of different joint models in stratified composite rock DEM simulation

作　　者：殷鹏飞[1] 杨圣奇[1,2] 高峰 田文岭[2] YIN Pengfei;YANG Shengqi;GAO Feng;TIAN Wenling(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou,Jiangsu221116,China)

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [2]中国矿业大学力学与土木工程学院,江苏徐州221116

出　　处：《采矿与安全工程学报》2023年第1期164-173,183,共11页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金青年项目(42202300);江苏省自然科学基金青年项目(BK20221150);中国矿业大学深部岩土国重专项项目(Z21003);中国矿业大学基本科研业务费项目-青年科技基金项目(2021QN1100)。

摘　　要：煤矿巷道围岩中广泛存在由不同岩性岩石组成的层状复合岩体,其变形破坏具有强烈的各向异性特征,对巷道的稳定安全会产生特殊的影响。目前,除了物理力学试验手段以外,离散元模拟被越来越广泛地应用到数值模拟研究中。本文以物理模拟试验为基础,在颗粒流模拟程序PFC^(2D)平台中分别采用删除颗粒黏结(bond removal method,BRM)和光滑节理模型(smooth joint model,SJM)2种节理面处理方式建立了层状复合岩石的模拟模型。模拟研究结果表明:SJM模拟模型可以更好地反映物理试验的应力—应变曲线形态,而BRM模型会在岩层倾角较大时产生较大的塑性变形,无法反映室内试验试样的脆性破坏特征。2种节理模型均可整体反映物理模拟试样的强度变形各向异性规律以及破坏模式,但SJM模型能更好地反映物理试样单轴压缩强度和弹性模量的各向异性特征,而BRM模型试样的宏观破裂面比SJM模型试样更加显著,与物理试样的破裂面更接近。另一方面,SJM节理模型能单独统计出SJM拉伸裂纹和剪切裂纹,通过分析这些裂纹的数目和分布区域可以更好地分析层状复合岩石试样破坏的细观机理。研究结论为后续离散元方法模拟层状复合岩体或节理岩体研究提供了积极的参考和指导。The stratified composite rock mass composed of different lithology rocks widely existed in the surrounding rock of roadway in coal mine,and its deformation and failure had strong anisotropy characteristics,which had a significant effect on the stability and safety of roadway.Discrete element method(DEM)had been widely employed into stratified rock simulation currently,in addition to physical and mechanical experiments.In this paper,the Particle Flow Code 2D(PFC^(2D))was employed to establish the transversely isotropic model of stratified rock.Two approaches available in PFC^(2D) were employed to simulate of joints.The bond removal method(BRM)and the smooth joint model(SJM),the BRM model and SJM model were individually employed to simulate the artificial transversely isotropic rock under uniaxial compression.Both of the two joint models synthetically reflected the strength anisotropy and failure behavior of stratified rock.Nevertheless,the SJM model simulated more effectively in uniaxial compressive strength(UCS)and elasticity modulus of stratified rock,while the failure pattern of BRM model was more remarkable and similar to artificial transversely isotropic rock.Besides,SJM model outputed smooth-joint crack counts and distribution individually,which revealed the mesoscopic failure mechanism of stratified rock.The research results provided positive reference and guidance for the subsequent DEM simulation of layered composite rock mass or jointed rock mass.

关 键 词：层状复合岩石 离散元法 PFC数值模拟 光滑节理模型 单轴压缩 

分 类 号：TU458[建筑科学—岩土工程]