基于微裂纹演化的煤层底板损伤破裂与渗流演化过程数值模拟
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摘要
基于岩石细观尺度微裂纹扩展演化的物理机制,将微裂纹损伤张量引入到经典的Biot孔隙弹性理论中,推导了岩石细观损伤演化与岩石宏观力学性能及渗透特性之间的联系,建立了基于微裂纹演化的岩石渗流-应力-损伤耦合模型与控制方程。利用MATLAB软件编程,将该耦合模型嵌入到COMSOL软件中,实现了流-固耦合作用下岩石损伤破裂及渗流演化过程动态模拟的数值程序。在此基础上,进行了承压水体上采煤的数值模拟,系统研究了煤层开采过程中底板裂隙损伤演化、破坏形态和渗流演化规律,深入揭示了煤层底板"渗流通道"形成及突水灾变的复杂演化过程和机理。
Based on the mechanisms of micro-crack growth, a micro-crack damage tensor has been introduced to the classical Biot's poroelasticity theory to deduce the relation between the microscopic damage evolution of rock and the macroscopic mechanical and hydraulic properties and to establish thehydro-mechanical coupling model and governing equation based on the fracturing evolution. Then the proposed model has been programmed with MATLAB and COMSOL to simulate the failure process and flow evolution of rock under hydro-mechanical couplings. On this basis, numerical simulations of coal mining above a confined aquifer have been performed and the mining-induced fracturing, failure patterns and flow evolution in coal seam floor have been analyzed systematically. The numerical results clearly show how the groundwater inrush channel is formed.
Based on the mechanisms of micro-crack growth, a micro-crack damage tensor has been introduced to the classical Biot's poroelasticity theory to deduce the relation between the microscopic damage evolution of rock and the macroscopic mechanical and hydraulic properties and to establish thehydro-mechanical coupling model and governing equation based on the fracturing evolution. Then the proposed model has been programmed with MATLAB and COMSOL to simulate the failure process and flow evolution of rock under hydro-mechanical couplings. On this basis, numerical simulations of coal mining above a confined aquifer have been performed and the mining-induced fracturing, failure patterns and flow evolution in coal seam floor have been analyzed systematically. The numerical results clearly show how the groundwater inrush channel is formed.
引文
[1]虎维岳,朱开鹏,黄选明.非均布高压水对采煤工作面底板隔水岩层破坏特征及其突水条件研究[J].煤炭学报,2010,35(7):1109-1114.HU Weiyue,ZHU Kaipeng,HUANG Xuanming.Study on floor rock mass failure and water inrush caused by non-uniform distributed water pressure in mining face[J].Journal of China Coal Society,2010,35(7):1109-1114.
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[6]缪协兴,浦海,白海波.隔水关键层原理及其在保水采煤中的应用研究[J].中国矿业大学学报,2008,37(1):1-4.MIAO Xiexing,PU Hai,BAI Haibo.Principle of waterresisting key strata and its application in water-preserved mining[J].Journal of China University of Mining&Technology,2008,37(1):1-4.
[7]王连国,宋扬.底板突水的非线性特征及预测[M].北京:煤炭工业出版社,2001:98-114.
[8]WANG J A,PARK H.Coal mining above a confined aquifer[J].International Journal of Rock Mechanics and Mining Sciences,2003,40(4):537-551.
[9]王金安,魏现昊,陈绍杰.承压水体上开采底板岩层破断及渗流特征[J].中国矿业大学学报,2012,41(4):536-542.WANG Jin’an,WEI Xianhao,CHEN Shaojie.Fracture and seepage characteristic in the floor strata when mining above a confined aquifer[J].Journal of China University of Mining&Technology,2012,41(4):536-542.
[10]李连崇,唐春安,梁正召,等.含断层煤层底板突水通道形成过程的仿真分析[J].岩石力学与工程学报,2009,28(2):290-297.LI Lianchong,TANG Chun’an,LIANG Zhengzhao,et al.Numerical analysis of pathway formation of groundwater inrush from faults in coal seam floor[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(2):290-297.
[11]杨天鸿,唐春安,谭志宏,等.岩体破坏突水模型研究现状及突水预测预报研究发展趋势[J].岩石力学与工程学报,2007,26(2):268-277.YANG Tianhong,TANG Chun’an,TAN Zhihong,et al.State of the art of inrush models in rock mass failure and developing trend for prediction and forecast of groundwater inrush[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(2):268-277.
[12]BIOT M A.General theory of three-dimensional consolidation[J].Journal of Applied Physics,1941,12(2):155-164.
[13]SHAO J F.Poroelastic behavior of brittle rock materials with anisotropic damage[J].Mechanics of Materials,1998,30(1):41-53.
[14]SHAO J F,LU Y,LYDZBA D.Damage modeling of saturated rocks in drained and undrained conditions[J].Journal of Engineering Mechanics,2004,130(6):733-739.
[15]CHENG A H D.Material coefficients of anisotropic poroelasticity[J].International Journal of Rock Mechanics and Mining Sciences,1997,34(2):199-205.
[16]余寿文,冯西桥.损伤力学[M].北京:清华大学出版社,1997:52-70.
[17]HOMAND-ETIENNE F,HOXHA D,SHAO J F.A continuum damage constitutive law for brittle rocks[J].Computers and Geotechnics,1998,22(2):135-151.
[18]SHAO J F,HOXHA D,BART M,et al.Modeling of induced anisotropic damage in granites[J].International Journal of Rock Mechanics and Mining Sciences,1999,36(8):1001-1012.
[19]ASHBY M F,HALLAM S D.The failure of brittle solids containing small cracks under compressive stress states[J].Acta Metallurgica,1986,34(3):497-510.
[20]KRAJCINOVIC D,FANELLA D.A micromechanical damage model for concrete[J].Engineering Fracture Mechanics,1986,25(5):585-596.
[21]ODA M,KATSUBE T,TAKEMURA T.Microcrack evolution and brittle failure of Inada granite in triaxial compression tests at 140 MPa[J].Journal of Geophysical Research:Solid Earth,2002,107(B10):ECV9-1-ECV9-17.
[22]COSTIN L.A microcrack model for the deformation and failure of brittle rock[J].Journal of Geophysical Research:Solid Earth,1983,88(B11):9485-9492.
[23]SHAO J F,CHAU K,FENG X.Modeling of anisotropic damage and creep deformation in brittle rocks[J].International Journal of Rock Mechanics and Mining Sciences,2006,43(4):582-592.
[24]GOLSHANI A,OKUI Y,ODA M,et al.A micromechanical model for brittle failure of rock and its relation to crack growth observed in triaxial compression tests of granite[J].Mechanics of Materials,2006,38(4):287-303.
[25]HALM D,DRAGON A.A model of anisotropic damage by mesocrack growth;unilateral effect[J].International Journal of Damage Mechanics,1996,5(4):384-402.
[26]SHAO J F,ZHOU H,CHAU K.Coupling between anisotropic damage and permeability variation in brittle rocks[J].International Journal for Numerical and Analytical Methods in Geomechanics,2005,29(12):1231-1247.
[27]杨天鸿.岩石破裂过程渗透性质及其与应力耦合作用研究[D].沈阳:东北大学,2001.
[28]赵阳升.多孔介质多场耦合作用及其工程响应[M].北京:科学出版社,2010:70-96.
[29]LU Y L,ELSWORTH D,WANG L G.Microcrack-based coupled damage and flow modeling of fracturing evolution in permeable brittle rocks[J].Computers and Geotechnics,2013,49(4):226-244.
[30]杨新安,郭鑫禾.矿井突水过程中的动力现象分析[J].矿山压力与顶板管理,1995,12(1):12-15.YANG Xin’an,GUO Xinhe.Analysis of dynamic phenomenon in mine water inrush process[J].Ground Pressure and Strata Control,1995,12(1):12-15.
[31]姜福兴,叶根喜,王存文,等.高精度微震监测技术在煤矿突水监测中的应用[J].岩石力学与工程学报,2008,27(9):1932-1938.JIANG Fuxing,YE Genxi,WANG Cunwen,et al.Application of high-precision microseismic monitoring technique to water inrush monitoring in coal mine[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(9):1932-1938.
[32]张金才,张玉卓,刘天泉.岩体渗流与煤层底板突水[M].北京:地质出版社,1997:32-51.
[2]武强,张志龙,马积福.煤层底板突水评价的新型实用方法I:主控指标体系的建设[J].煤炭学报,2007,32(1):42-47.WU Qiang,ZHANG Zhilong,MA Jifu.A new practical methodology of the coal floor water bursting evaluating I:the master controlling index system construction[J].Journal of China Coal Society,2007,32(1):42-47.
[3]武强,张志龙,张生元,等.煤层底板突水评价的新型实用方法Ⅱ:脆弱性指数法[J].煤炭学报,2007,32(11):1121-1126.WU Qiang,ZHANG Zhilong,ZHANG Shengyuan,et al.A new practical methodology of the coal floor water bursting evaluating II:the vulnerable index method[J].Journal of China Coal Society,2007,32(11):1121-1126.
[4]李白英.预防矿井底板突水的“下三带”理论及其发展与应用[J].山东矿业学院学报,1999,18(4):11-18.LI Baiying.“Down three zones”in the prediction of the water inrush from coalbed floor aquifer-theory,development and application[J].Journal of Shandong Institute of Mining and Technology,1999,18(4):11-18.
[5]王经明.承压水沿煤层底板递进导升突水机理的模拟与观测[J].岩土工程学报,1999,21(5):546-549.WANG Jingming.In-situ measurement and physical analogue on water inrush from coal floor induced by progressive intrusion of artesian water into protective aquiclude[J].Chinese Journal of Geotechnical Engineering,1999,21(5):546-549.
[6]缪协兴,浦海,白海波.隔水关键层原理及其在保水采煤中的应用研究[J].中国矿业大学学报,2008,37(1):1-4.MIAO Xiexing,PU Hai,BAI Haibo.Principle of waterresisting key strata and its application in water-preserved mining[J].Journal of China University of Mining&Technology,2008,37(1):1-4.
[7]王连国,宋扬.底板突水的非线性特征及预测[M].北京:煤炭工业出版社,2001:98-114.
[8]WANG J A,PARK H.Coal mining above a confined aquifer[J].International Journal of Rock Mechanics and Mining Sciences,2003,40(4):537-551.
[9]王金安,魏现昊,陈绍杰.承压水体上开采底板岩层破断及渗流特征[J].中国矿业大学学报,2012,41(4):536-542.WANG Jin’an,WEI Xianhao,CHEN Shaojie.Fracture and seepage characteristic in the floor strata when mining above a confined aquifer[J].Journal of China University of Mining&Technology,2012,41(4):536-542.
[10]李连崇,唐春安,梁正召,等.含断层煤层底板突水通道形成过程的仿真分析[J].岩石力学与工程学报,2009,28(2):290-297.LI Lianchong,TANG Chun’an,LIANG Zhengzhao,et al.Numerical analysis of pathway formation of groundwater inrush from faults in coal seam floor[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(2):290-297.
[11]杨天鸿,唐春安,谭志宏,等.岩体破坏突水模型研究现状及突水预测预报研究发展趋势[J].岩石力学与工程学报,2007,26(2):268-277.YANG Tianhong,TANG Chun’an,TAN Zhihong,et al.State of the art of inrush models in rock mass failure and developing trend for prediction and forecast of groundwater inrush[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(2):268-277.
[12]BIOT M A.General theory of three-dimensional consolidation[J].Journal of Applied Physics,1941,12(2):155-164.
[13]SHAO J F.Poroelastic behavior of brittle rock materials with anisotropic damage[J].Mechanics of Materials,1998,30(1):41-53.
[14]SHAO J F,LU Y,LYDZBA D.Damage modeling of saturated rocks in drained and undrained conditions[J].Journal of Engineering Mechanics,2004,130(6):733-739.
[15]CHENG A H D.Material coefficients of anisotropic poroelasticity[J].International Journal of Rock Mechanics and Mining Sciences,1997,34(2):199-205.
[16]余寿文,冯西桥.损伤力学[M].北京:清华大学出版社,1997:52-70.
[17]HOMAND-ETIENNE F,HOXHA D,SHAO J F.A continuum damage constitutive law for brittle rocks[J].Computers and Geotechnics,1998,22(2):135-151.
[18]SHAO J F,HOXHA D,BART M,et al.Modeling of induced anisotropic damage in granites[J].International Journal of Rock Mechanics and Mining Sciences,1999,36(8):1001-1012.
[19]ASHBY M F,HALLAM S D.The failure of brittle solids containing small cracks under compressive stress states[J].Acta Metallurgica,1986,34(3):497-510.
[20]KRAJCINOVIC D,FANELLA D.A micromechanical damage model for concrete[J].Engineering Fracture Mechanics,1986,25(5):585-596.
[21]ODA M,KATSUBE T,TAKEMURA T.Microcrack evolution and brittle failure of Inada granite in triaxial compression tests at 140 MPa[J].Journal of Geophysical Research:Solid Earth,2002,107(B10):ECV9-1-ECV9-17.
[22]COSTIN L.A microcrack model for the deformation and failure of brittle rock[J].Journal of Geophysical Research:Solid Earth,1983,88(B11):9485-9492.
[23]SHAO J F,CHAU K,FENG X.Modeling of anisotropic damage and creep deformation in brittle rocks[J].International Journal of Rock Mechanics and Mining Sciences,2006,43(4):582-592.
[24]GOLSHANI A,OKUI Y,ODA M,et al.A micromechanical model for brittle failure of rock and its relation to crack growth observed in triaxial compression tests of granite[J].Mechanics of Materials,2006,38(4):287-303.
[25]HALM D,DRAGON A.A model of anisotropic damage by mesocrack growth;unilateral effect[J].International Journal of Damage Mechanics,1996,5(4):384-402.
[26]SHAO J F,ZHOU H,CHAU K.Coupling between anisotropic damage and permeability variation in brittle rocks[J].International Journal for Numerical and Analytical Methods in Geomechanics,2005,29(12):1231-1247.
[27]杨天鸿.岩石破裂过程渗透性质及其与应力耦合作用研究[D].沈阳:东北大学,2001.
[28]赵阳升.多孔介质多场耦合作用及其工程响应[M].北京:科学出版社,2010:70-96.
[29]LU Y L,ELSWORTH D,WANG L G.Microcrack-based coupled damage and flow modeling of fracturing evolution in permeable brittle rocks[J].Computers and Geotechnics,2013,49(4):226-244.
[30]杨新安,郭鑫禾.矿井突水过程中的动力现象分析[J].矿山压力与顶板管理,1995,12(1):12-15.YANG Xin’an,GUO Xinhe.Analysis of dynamic phenomenon in mine water inrush process[J].Ground Pressure and Strata Control,1995,12(1):12-15.
[31]姜福兴,叶根喜,王存文,等.高精度微震监测技术在煤矿突水监测中的应用[J].岩石力学与工程学报,2008,27(9):1932-1938.JIANG Fuxing,YE Genxi,WANG Cunwen,et al.Application of high-precision microseismic monitoring technique to water inrush monitoring in coal mine[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(9):1932-1938.
[32]张金才,张玉卓,刘天泉.岩体渗流与煤层底板突水[M].北京:地质出版社,1997:32-51.