采动覆岩渐进破坏的连续–离散耦合模拟研究  

Continuous-discrete coupling simulation of progressive failure of mining overburden rock

作　　者：李浩[1] 唐世斌[2,3] 马立强[4] 白海波[5] 康志勤[1] 武鹏飞[1] 缪小成 LI Hao;TANG Shibin;MA Liqiang;BAI Haibo;KANG Zhiqin;WU Pengfei;MIAO Xiaocheng(Key Laboratory of In-situ Property Improving Mining of Ministry of Education,Taiyuan University of Technology,Taiyuan,Shanxi 030024,China;School of Civil Engineering,Dalian University of Technology,Dalian,Liaoning 116024,China;Institute of Rock Instability and Seismicity Research,Dalian University of Technology,Dalian,Liaoning 116024,China;School of Mining Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Jinneng Holding Coal Industry Group,Datong,Shanxi 037003,China)

机构地区：[1]太原理工大学原位改性采矿教育部重点实验室,山西太原030024 [2]大连理工大学土木工程学院,辽宁大连116024 [3]大连理工大学岩石破裂与失稳研究所,辽宁大连116024 [4]中国矿业大学矿业工程学院,江苏徐州221116 [5]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 [6]晋能控股煤业集团,山西大同037003

出　　处：《岩石力学与工程学报》2022年第11期2299-2310,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(42102310);山西省应用基础研究计划(20210302123106)。

摘　　要：采动覆岩破裂演化数值结果准确性的关键在于建立岩体渐进破坏本构与连续–离散模拟方法。构建偏应力、球应力为基本变量的屈服函数、塑性势函数,结合广义胡克定律得到完整岩块的弹塑性本构;引入弹塑性损伤理论,以平方拉剪应力准则为初始损伤判据,结合Benzeggagh-Kenane断裂准则,得到拉剪混合型断裂本构;构建离散块体挤压本构,基于直剪实验数据修正Sargin粗糙结构面剪切摩擦本构。编制反映岩石渐进破坏的连续–离散耦合模拟计算程序,在验证本构模型的基础上,根据同煤工程地质条件建立数值计算模型。结果表明:(1)岩石渐进破坏本构方程及相应的连续–离散耦合模拟方法,可数值实现岩石从连续体到离散体的转变过程;(2)多煤层重复开采扰动下,石炭系煤层覆岩裂隙分布复杂,其高度约为采高的21倍,远超经验公式所得结果;(3)模拟条件下,在侏罗系煤柱集中应力和采动应力耦合作用下,石炭系工作面超前支承压力峰值达到42 MPa,较无煤柱区域提高8~10 MPa,矿压显现强烈。上述成果在大同矿区得到初步应用,为进一步开展保水采煤、压裂卸压等提供理论支撑。The key to the accuracy of the numerical results of the fracture evolution of mining overburden is to establish the mechanical constitutive model and numerical method reflecting the continuous-discrete medium transformation of mining rock.The yield function and plastic potential function with deviatoric stress and spherical stress as basic variables were constructed,and the elastic-plastic constitutive model of complete rock block was obtained by combining with generalized Hooke’s law.By introducing the elastic-plastic damage theory,taking the square tensile-shear stress criterion as the initial damage criterion and combined with the Benzeggagh-Kenane fracture criterion,the constitutive model of tensile-shear mixed mode fracture was obtained.The discrete block compression constitutive model was constructed,and the Sargin’s shear friction constitutive model of rough discontinuities was modified based on the direct shear experimental data.Therefore,a continuous-discrete coupling simulation program reflecting the progressive failure of rock was compiled.On the basis of verifying the constitutive model,the numerical calculation model was established according to the engineering geological conditions of the DaTong mine.The results show that:(1)The progressive failure constitutive model of rock and the corresponding continuous-discrete coupling simulation method can numerically realize the transformation process of rock from continuum to discrete body.(2)Under the disturbance of repeated mining in multiple coal seams,the distribution of overburden fractures in Carboniferous coal seams is complex,and its height is about 21 times of the mining height,far exceeding the results obtained by empirical formula.(3)Under the coupling action of concentrated stress and mining stress of Jurassic coal pillar,the peak value of advanced support pressure of Carboniferous mining face reaches 42 MPa,which is about 8–10 MPa higher than that in the area without coal pillar,and the ground pressure shows strongly.The above results hav

关 键 词：岩石力学 覆岩运动 渐进破坏 连续–离散介质 混合型断裂 压剪摩擦 

分 类 号：TU45[建筑科学—岩土工程]