加卸荷应力路径下巷帮煤体力学特性与损伤破坏研究
|
摘要
为探究煤巷开挖卸荷帮部破坏机理,开展巷帮煤体常规三轴压缩及峰前卸围压2种应力路径下实验室试验,分析其力学特性与损伤破坏规律。结果表明:常规三轴压缩试验中,破坏特征表现出由低围压下的脆性向高围压下的塑形转变;峰前卸围压应力路径下,破坏更易发生,且全部为脆性破坏;煤体强度对围压变化较敏感,卸荷条件下其峰值更低;变形模量随围压被卸除而降低,开始阶段变化平缓,随后下降趋势不断加剧;泊松比随围压减小而增大,其变化趋势同变形模量基本一致;卸荷应力路径下,煤体破坏是一种以剪切破坏为主,但仍存在部分劈裂破坏的复合状态;破断角以抛物线趋势随初始围压的提高而增加,但卸荷应力路径下其值明显更小;卸荷条件下损伤因子与围压之间的变化关系及趋势同泊松比一致;随初始围压的增加,卸荷条件下围压差比λ逐渐降低。
To explore side wall breakage mechanism of coal roadway for excavation unloading,laboratory tests of coal mass in roadway side wall under loading and unloading stress paths were conducted,and its mechanical properties and damage failure were analyzed.The results indicated that in conventional triaxial compression test,with the raise of confining pressure,failure characteristics of coal mass would be changed from brittleness to ductility.Under stress path of confining pressure reduction,failures were more likely to happen and all of them were brittle failure.Coal mass strength was very sensitive to confining pressure variations and its peak value was lower under unloading stress path.Deformation modulus decreased with the reduction of confining pressure,change was gentle in the initial stage,but the downtrend was aggravated continuously by later.Poisson ratio increased as confining pressure conduction and its variation trend agreed with modulos of deformation.Under unloading stress path,coal mass failure was a composite state,in which shear failure was the chief form,but splitting failure also might appear.Fracture angle increased with the raise of initial confining pressure along a parabolic curve,but its value was obviously smaller under unloading stress path.Under unloading stress path,the relationship and variation trend between damage factor and confining pressure agreed with poisson ratio. Confining pressure difference ratio decreased with the raise of initial confining pressure under unloading stress path.
To explore side wall breakage mechanism of coal roadway for excavation unloading,laboratory tests of coal mass in roadway side wall under loading and unloading stress paths were conducted,and its mechanical properties and damage failure were analyzed.The results indicated that in conventional triaxial compression test,with the raise of confining pressure,failure characteristics of coal mass would be changed from brittleness to ductility.Under stress path of confining pressure reduction,failures were more likely to happen and all of them were brittle failure.Coal mass strength was very sensitive to confining pressure variations and its peak value was lower under unloading stress path.Deformation modulus decreased with the reduction of confining pressure,change was gentle in the initial stage,but the downtrend was aggravated continuously by later.Poisson ratio increased as confining pressure conduction and its variation trend agreed with modulos of deformation.Under unloading stress path,coal mass failure was a composite state,in which shear failure was the chief form,but splitting failure also might appear.Fracture angle increased with the raise of initial confining pressure along a parabolic curve,but its value was obviously smaller under unloading stress path.Under unloading stress path,the relationship and variation trend between damage factor and confining pressure agreed with poisson ratio. Confining pressure difference ratio decreased with the raise of initial confining pressure under unloading stress path.
引文
[1]夏孝够.深井回采巷道围岩变形机理及支护技术研究[D].淮南:安徽理工大学,2006.
[2]哈秋舲,李建林,张永兴,等.节理岩体卸荷非线性岩体力学[M].北京:中国建筑工业出版社,1998.
[3]李建林,熊俊华,杨学堂.岩体卸荷力学特性的试验研究[J].水利水电技术,2001,32(5):48-51.LI Jianlin,XIONG Junhua,YANG Xuetang.Experimental study on mechanical characteristics of unloading rock mass[J].Water Resources and Hydropower Engineering,2001,32(5):48-51.
[4]LAU J S O,CHANDLER N A.Innovative laboratory testing[J].International Journal of Rock Mechanics and Mining Sciences,2004,41(8):1427-1445.
[5]高春玉,徐进,何鹏,等.大理岩加卸载力学特性的研究[J].岩石力学与工程学报,2005,24(3):456-460.GAO Chunyu,XU Jin,HE Peng,et al.Study on mechanical properties of marble under loading and unloading conditions[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(3):456-460.
[6]李宏哲,夏才初,闫子舰,等.锦屏水电站大理岩在高应力条件下的卸荷力学特性研究[J].岩石力学与工程学报,2007,26(10):2104-2109.LI Hongzhe,XIA Caichu,YAN Zijian,et al.Study on marble unloading mechanical properties of jinping hydropower station under high geostress conditions[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(10):2104-2109.
[7]黄润秋,黄达.卸荷条件下花岗岩力学特性试验研究[J].岩石力学与工程学报,2008,27(11):2205-2213.HUANG Runqiu,HUANG Da.Experimental research on mechanical properties of granites under unloading condition[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(11):2205-2213.
[8]黄润秋,黄达.高地应力条件下卸荷速率对锦屏大理岩力学特性影响规律试验研究[J].岩石力学与工程学报,2010,29(1):21-33.HUANG Runqiu,HUANG Da.Experimental research on affection laws of unloading rates on mechanical properties of jinping marble under high geostress[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(1):21-33.
[9]周小平,哈秋聆,张永兴,等.峰前围压卸荷条件下岩石的应力-应变全过程分析和变形局部化研究[J].岩石力学与工程学报,2005,24(18):3236-3245.ZHOU Xiaoping,HA Qiuling,ZHANG Yongxing,et al.Analysis of localization of deformation and complete stress-strain relation for mesoscopic heterogenous brittle rock materials when axial stress isheld constant while lateral confinement is reduced[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(18):3236-3245.
[10]郭印同,杨春和,付建军.盐岩三轴卸荷力学特性试验研究[J].岩土力学,2012,33(3):725-730.GUO Yintong,YANG Chunhe,FU Jianjun.Experimental research on mechanical characteristics of salt rock under triaxial unloading test[J].Rock and Soil Mechanics,2012,33(3):725-730.
[11]SWANSSON S R,BROWN W S.An observation of loading path independence of fracture in rock[J].International Journal of Rock Mechanics&Mining Sciences,1971,8(3):277-281.
[12]陈旦熹,戴冠一.三向应力状态下大理岩压缩变形试验研究[J].岩土力学,1982,3(1):27-44.CHEN Danxi,DAI Guanyi.Experimental study on compressive deformation of marble under triaxial stress states[J].Rock and Soil Mechanics,1982,3(1):27-44.
[13]吴刚.岩体在加,卸荷条件下破坏效应的对比分析[J].岩土力学,1997,18(2):13-16.WU Gang.Comparison of failure effects of rock mass under loading and unloading conditions[J].Rock and Soil Mechanics,1997,18(2):13-16.
[14]陈卫忠,吕森鹏,郭小红,等.脆性岩石卸围压试验与岩爆机理研究[J].岩土工程学报,2010,32(6):963-969.CHEN Weizhong,LYU Senpeng,GUO Xiaohong,et al.Unloading confining pressure for brittle rock and mechanism of rock burst[J].Chinese Journal of Geotechnical Engineering,2010,32(6):963-969.
[15]温韬,刘佑荣,胡政,等.高应力区砂岩加卸载条件下能量变化规律及损伤分析[J].地质科技情报,2015,32(2):200-206.WEN Tao,LIU Yourong,HU Zheng,et al.Energy change law damage analysis of sandstone under loading and unloading conditions in high stress area[J].Geological Science and Technology Information,2015,32(2):200-206.
[16]ZHAO G Y,DAI B,DONG L J,et al.Energy conversion of rocks in process of unloading confining pressure under different unloading paths[J].Transactions of Nonferrous Metals Society of China,2015,25(5):1626-1632.
[17]苏承东,高保彬,南华,等.不同应力路径下煤样变形破坏过程声发射特征的试验研究[J].岩石力学与工程学报,2009,28(4):757-766.SU Chengdong,GAO Baobin,NAN Hua,et al.Experimental study on acoustic emission characteristics during deformation and failure processes of coal samples under different stress paths[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(4):757-766.
[18]刘泉声,刘恺德,朱杰兵,等.高应力下原煤三轴压缩力学特性研究[J].岩石力学与工程学报,2014,33(1):24-34.LIU Quansheng,LIU Kaide,ZHU Jiebing,et al.Study of mechanical properties of raw coal under high stress with triaxial compression[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(1):24-34.
[19]张军伟,姜德义,赵云峰,等.分阶段卸荷过程中构造煤的力学特征及能量演化分析[J].煤炭学报,2015,40(12):2820-2828.ZHANG Junwei,JIANG Deyi,ZHAO Yunfeng,et al.Analysis of the mechanical characteristics and energy evolution of tectonic coal during the process of step unloading[J].Journal of China Coal Society,2015,40(12):2820-2828.
[20]张成良,赵晓霞.辉绿岩在加、卸荷条件下的岩体力学特性试验[J].煤炭学报,2011,36(S2):224-230.ZHANG Chengliang,ZHAO Xiaoxia.Experiment on mechanics properties of diabase under the press of loading and unloading[J].Journal of China Coal Society,2011,36(S2):224-230.
[2]哈秋舲,李建林,张永兴,等.节理岩体卸荷非线性岩体力学[M].北京:中国建筑工业出版社,1998.
[3]李建林,熊俊华,杨学堂.岩体卸荷力学特性的试验研究[J].水利水电技术,2001,32(5):48-51.LI Jianlin,XIONG Junhua,YANG Xuetang.Experimental study on mechanical characteristics of unloading rock mass[J].Water Resources and Hydropower Engineering,2001,32(5):48-51.
[4]LAU J S O,CHANDLER N A.Innovative laboratory testing[J].International Journal of Rock Mechanics and Mining Sciences,2004,41(8):1427-1445.
[5]高春玉,徐进,何鹏,等.大理岩加卸载力学特性的研究[J].岩石力学与工程学报,2005,24(3):456-460.GAO Chunyu,XU Jin,HE Peng,et al.Study on mechanical properties of marble under loading and unloading conditions[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(3):456-460.
[6]李宏哲,夏才初,闫子舰,等.锦屏水电站大理岩在高应力条件下的卸荷力学特性研究[J].岩石力学与工程学报,2007,26(10):2104-2109.LI Hongzhe,XIA Caichu,YAN Zijian,et al.Study on marble unloading mechanical properties of jinping hydropower station under high geostress conditions[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(10):2104-2109.
[7]黄润秋,黄达.卸荷条件下花岗岩力学特性试验研究[J].岩石力学与工程学报,2008,27(11):2205-2213.HUANG Runqiu,HUANG Da.Experimental research on mechanical properties of granites under unloading condition[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(11):2205-2213.
[8]黄润秋,黄达.高地应力条件下卸荷速率对锦屏大理岩力学特性影响规律试验研究[J].岩石力学与工程学报,2010,29(1):21-33.HUANG Runqiu,HUANG Da.Experimental research on affection laws of unloading rates on mechanical properties of jinping marble under high geostress[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(1):21-33.
[9]周小平,哈秋聆,张永兴,等.峰前围压卸荷条件下岩石的应力-应变全过程分析和变形局部化研究[J].岩石力学与工程学报,2005,24(18):3236-3245.ZHOU Xiaoping,HA Qiuling,ZHANG Yongxing,et al.Analysis of localization of deformation and complete stress-strain relation for mesoscopic heterogenous brittle rock materials when axial stress isheld constant while lateral confinement is reduced[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(18):3236-3245.
[10]郭印同,杨春和,付建军.盐岩三轴卸荷力学特性试验研究[J].岩土力学,2012,33(3):725-730.GUO Yintong,YANG Chunhe,FU Jianjun.Experimental research on mechanical characteristics of salt rock under triaxial unloading test[J].Rock and Soil Mechanics,2012,33(3):725-730.
[11]SWANSSON S R,BROWN W S.An observation of loading path independence of fracture in rock[J].International Journal of Rock Mechanics&Mining Sciences,1971,8(3):277-281.
[12]陈旦熹,戴冠一.三向应力状态下大理岩压缩变形试验研究[J].岩土力学,1982,3(1):27-44.CHEN Danxi,DAI Guanyi.Experimental study on compressive deformation of marble under triaxial stress states[J].Rock and Soil Mechanics,1982,3(1):27-44.
[13]吴刚.岩体在加,卸荷条件下破坏效应的对比分析[J].岩土力学,1997,18(2):13-16.WU Gang.Comparison of failure effects of rock mass under loading and unloading conditions[J].Rock and Soil Mechanics,1997,18(2):13-16.
[14]陈卫忠,吕森鹏,郭小红,等.脆性岩石卸围压试验与岩爆机理研究[J].岩土工程学报,2010,32(6):963-969.CHEN Weizhong,LYU Senpeng,GUO Xiaohong,et al.Unloading confining pressure for brittle rock and mechanism of rock burst[J].Chinese Journal of Geotechnical Engineering,2010,32(6):963-969.
[15]温韬,刘佑荣,胡政,等.高应力区砂岩加卸载条件下能量变化规律及损伤分析[J].地质科技情报,2015,32(2):200-206.WEN Tao,LIU Yourong,HU Zheng,et al.Energy change law damage analysis of sandstone under loading and unloading conditions in high stress area[J].Geological Science and Technology Information,2015,32(2):200-206.
[16]ZHAO G Y,DAI B,DONG L J,et al.Energy conversion of rocks in process of unloading confining pressure under different unloading paths[J].Transactions of Nonferrous Metals Society of China,2015,25(5):1626-1632.
[17]苏承东,高保彬,南华,等.不同应力路径下煤样变形破坏过程声发射特征的试验研究[J].岩石力学与工程学报,2009,28(4):757-766.SU Chengdong,GAO Baobin,NAN Hua,et al.Experimental study on acoustic emission characteristics during deformation and failure processes of coal samples under different stress paths[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(4):757-766.
[18]刘泉声,刘恺德,朱杰兵,等.高应力下原煤三轴压缩力学特性研究[J].岩石力学与工程学报,2014,33(1):24-34.LIU Quansheng,LIU Kaide,ZHU Jiebing,et al.Study of mechanical properties of raw coal under high stress with triaxial compression[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(1):24-34.
[19]张军伟,姜德义,赵云峰,等.分阶段卸荷过程中构造煤的力学特征及能量演化分析[J].煤炭学报,2015,40(12):2820-2828.ZHANG Junwei,JIANG Deyi,ZHAO Yunfeng,et al.Analysis of the mechanical characteristics and energy evolution of tectonic coal during the process of step unloading[J].Journal of China Coal Society,2015,40(12):2820-2828.
[20]张成良,赵晓霞.辉绿岩在加、卸荷条件下的岩体力学特性试验[J].煤炭学报,2011,36(S2):224-230.ZHANG Chengliang,ZHAO Xiaoxia.Experiment on mechanics properties of diabase under the press of loading and unloading[J].Journal of China Coal Society,2011,36(S2):224-230.