河下浅埋厚煤层采动覆岩裂隙-涌水量时空演化的FDEM-CFD耦合分析  

FDEM-CFD coupling analysis of spatiotemporal evolution of mining-induced overburden fracture-water inflow in shallow and thick coal seam under river

作　　者：杨泽斌 李浩[1] 马立强[2] 麦龙泉 YANG Zebin;LI Hao;MA Liqiang;MAI Longquan(Key Laboratory of In-situ Property Improving Mining of Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China;China University of Mining and Technology School of Mining Engineering,Xuzhou 221116,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]中国矿业大学矿业工程学院,江苏徐州211116

出　　处：《煤炭科学技术》2024年第6期176-184,共9页Coal Science and Technology

基　　金：国家自然科学基金资助项目(42102310);山西省基础研究计划资助项目(20210302123106);陕西省煤矿水害防治技术重点实验室开放基金资助项目(2021SKMS03)。

摘　　要：河下浅埋厚煤层采动覆岩裂隙分布与涌水量是工作面安全生产的决定性因素之一。数值模拟是二者重要预测方法,其合理性的关键在于建立岩体破坏-裂隙流体耦合理论及相应的模拟方法。以路家村矿15404工作面为研究背景,构建拉/剪应力下非贯通裂隙开裂、贯通裂隙的法向与切向本构关系,并基于二相流质量守恒、动量守恒与状态方程,结合增强的浸没边界算法识别流-固界面,通过流体体积法实现裂隙内流体自由面的追踪和重构。在此基础上形成FDEM-CFD河下采煤覆岩裂隙与涌水量预测数值模型耦合程序,通过相邻工作面地面钻孔冲洗液消耗量观测法验证导水裂隙带发育高度,以及采用大井法理论对涌水量结果进行对比。结果表明:采动岩体破坏-裂隙流体耦合理论及相应的FDEM-CFD程序,可数值实现河下浅埋厚煤层采动覆岩裂隙形成,以及裂隙内流体运移过程。当工作面推进至80~120 m时覆岩内形成贯通地表的导水裂隙。招山河水的主要下泄路径为工作面后方8~20 m位置处的导水裂隙,其斜向采空区、倾角65°~72°。模拟所得采空区涌水量为18.78 m^(3)/h,与大井法计算结果接近。上述成果在路家村矿区得到初步应用,为进一步开展河下浅埋厚煤层防治水工程提供理论支撑。The distribution of overlying rock fractures and water inflow during mining in shallow and thick coal seams under the river is one of the decisive factors for the safe production of working faces.Numerical simulation is an important prediction method for both,and the key to its rationality lies in the establishment of a rock mass failure fracture fluid coupling theory and corresponding simulation methods.Taking the 15404 working face of Lujiacun Mine as the research background,the normal and tangential constitutive relationships of non through crack cracking and through crack under tensile/shear stress are constructed.Based on the conservation of mass,momentum,and state equations of two-phase flow,the enhanced immersion boundary algorithm is combined to identify the fluid solid interface.The fluid volume method is used to track and reconstruct the fluid free surface inside the crack.On this basis,a coupling program of FDEMCFD numerical model for predicting overlying rock fractures and water inflow in coal mining under the river is formed.The development height of the water conducting fracture zone is verified through the observation of the consumption of flushing fluid in adjacent working faces, and the results of water inflow are compared using the large well method theory. The results indicate that the coupling theory ofmining rock mass failure and fracture fluid, as well as the corresponding FDEM-CFD program, can numerically achieve the formation ofoverlying rock fractures in shallow and thick coal seams under rivers during mining, as well as the fluid transport process within the fractures.When the working face advances to 80-120 m, a water conducting crack that runs through the surface is formed within the overlyingrock. The main discharge path of the Zhaoshan River is the water diversion fissure located about 8-20 m behind the working face, which isinclined towards the goaf and has an inclination angle of about 65°-72°. The simulated water inflow in the goaf is 18.78 m^(3)/h, which isclose to the calculat

关 键 词：河下浅埋煤层 覆岩裂隙 涌水量 本构模型 FDEM-CFD耦合 

分 类 号：TD745[矿业工程—矿井通风与安全]