考虑刚度和强度劣化时弱胶结软岩巷道围岩的弹塑性损伤分析
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摘要
岩体内部微裂纹的存在及其扩展,会导致岩体产生刚度和强度劣化,使巷道围岩松动范围扩大。通过定义刚度劣化系数和强度劣化系数,考虑弱胶结软岩峰后应变软化和塑性扩容特性,采用损伤理论和三直线应变软化模型,建立了弱胶结软岩巷道围岩弹塑性流动损伤模型,推导了非均匀应力场下围岩分别产生弹性损伤区、塑性软化损伤区和塑性流动损伤区时的应力、位移解析解;探讨了鲁新煤矿弱胶结砂质泥岩巷道的原岩应力水平、刚度劣化、扩容梯度等对围岩的损伤演化及位移场、塑性圈的影响规律。结果表明,剪胀效应对围岩塑性圈的大小及应力响应影响不大,但对塑性区的损伤速度及位移影响很大;原岩应力水平对巷道塑性圈的分布具有显著影响;刚度和强度劣化系数的增大会加快围岩的劣化速度。这些因素在围岩稳定性分析及巷道支护设计中均应引起足够重视。
The cracking of stiffness and strength,due to existing and development of micro cracks in elastic region,causes the loosening scope of roadway surrounding rock expanded.By defining stiffness cracking coefficient and strength cracking factor,considering characteristics of strain softening and plastic dilatancy after post-peak,the article established an elastic-plastic flow damage model for weakly consolidated soft rock under non-uniform initial stress field on the basis of damage theory and strain softening model with three linear steps;inferred analytical solutions of stresses,displacements when surrounding rock generate three different failure areas: elastic zone,elastic and plastic softening zone,and plastic flow zone;and discussed the rule on the influence of original rock stress,strength cracking,dilatancy gradient of soft surrounding rock in Luxin coal mine on damage evolution,displacement and plastic circle of surrounding rock.Results show that dilatancy gradient has great effect on damage speed and displacements in plastic zone while it has little effect on the size of plastic circle and stress responses;that original rock stress level has remarkable influence on the distribution of plastic circle of the roadway;and that the rising of stiffness and strengthen cracking coefficient will accelerate the cracking speed of surrounding rock,which should be paid enough attention in analyzing the stability of the surrounding rock and designing weakly consolidated soft rock tunnel.
The cracking of stiffness and strength,due to existing and development of micro cracks in elastic region,causes the loosening scope of roadway surrounding rock expanded.By defining stiffness cracking coefficient and strength cracking factor,considering characteristics of strain softening and plastic dilatancy after post-peak,the article established an elastic-plastic flow damage model for weakly consolidated soft rock under non-uniform initial stress field on the basis of damage theory and strain softening model with three linear steps;inferred analytical solutions of stresses,displacements when surrounding rock generate three different failure areas: elastic zone,elastic and plastic softening zone,and plastic flow zone;and discussed the rule on the influence of original rock stress,strength cracking,dilatancy gradient of soft surrounding rock in Luxin coal mine on damage evolution,displacement and plastic circle of surrounding rock.Results show that dilatancy gradient has great effect on damage speed and displacements in plastic zone while it has little effect on the size of plastic circle and stress responses;that original rock stress level has remarkable influence on the distribution of plastic circle of the roadway;and that the rising of stiffness and strengthen cracking coefficient will accelerate the cracking speed of surrounding rock,which should be paid enough attention in analyzing the stability of the surrounding rock and designing weakly consolidated soft rock tunnel.
引文
[1]陆银龙,王连国,杨峰,等.软弱岩石峰后应变软化力学特性研究[J].岩石力学与工程学报,2010,29(3):640-648.LU Yin-long,WANG Lian-guo,YANG Feng,et al.Post-peak strain softening mechanical properties[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(3):640-648.
[2]李政林,吴瑞祥,李龙剑,等.基于损伤理论的隧道围岩松动圈确定方法[J].地下空间与工程学报,2011,7(6):1060-1064.LI Zheng-lin,WU Rui-xiang,LI Long-jian,et al.Method for defining the loose zone of tunnel surrounding rock based on damage theory[J].Chinese Journal of Underground Space and Engineering,2011,7(6):1060-1064.
[3]马青,赵均海,魏雪英,等.基于损伤理论的圆形隧洞围岩应力场分析[J].建筑科学与工程学报,2011,28(2):84-94.MA Qing,ZHAO Jun-hai,WEI Xue-ying,et al.Stress field analysis of circular tunnel surrounding rock based on damage theory[J].Journal of Architecture and Civil Engineering,2011,28(2):84-94.
[4]张强,王水林,葛修润.圆形巷道围岩应变软化弹塑性分析[J].岩石力学与工程学报,2010,29(5):1031-1035.ZHANG Qiang,WANG Shui-lin,GE Xiu-run.Elastoplastic anslysis of circular openings in strainsoftening rock masses[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(5):1031-1035.
[5]王水林,吴振君,李春光,等.应变软化模拟与圆形隧道衬砌分析[J].岩土力学,2010,31(6):1929-1936.WANG Shui-lin,WU Zhen-jun,LI Chun-guang,et al.Modeling of strain-softening and analysis of a lining for circular tunnel[J].Rock and Soil Mechanics,2010,31(6):1929-1936.
[6]张常光,徐飞,张庆贺,等.岩石隧道塑性位移新解[J].岩石力学与工程学报,2011,30(增刊2):3551-3556.ZHANG Chang-guang,XU Fei,ZHANG Qing-he,et al.New plastic solution for displacement of rock tunnels[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(Supp 2):3551-3556.
[7]蒋斌松,张强,贺永年,等.深部圆形巷道破裂围岩的弹塑性分析[J].岩石力学与工程学报,2007,26(5):982-986.JIANG Bin-song,ZHANG Qiang,HE Yong-nian,et al.Elasto-plastic analysis of cracked surrounding rocks in deep circular openings[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(5):982-986
[8]潘阳,赵光明,孟祥瑞.非均匀应力场下巷道围岩弹塑性分析[J].煤炭学报,2011,36(增刊1):53-57.PAN Yang,ZHAO Guang-ming,MENG Xiang-rui.Elasto-plastic analysis on surrounding rock mass under non-uniform stress field[J].Journal of China Coal Society,2011,36(Supp 1):53-57.
[9]陈立伟,彭建兵,范文,等.基于统一强度理论的非均匀应力场圆形巷道围岩塑性区分析[J].煤炭学报,2007,32(1):20-23.CHEN Li-wei,PENG Jian-bing,FAN Wen,et al.Analysis of surrounding rock mass plastic zone of round tunnel under non-uniform stress field based on the unified strength theory[J].Journal of China Coal Society,2007,32(1):20-23.
[10]王唢,赵明阶,蒋树屏,等.隧道开挖中围岩损伤演化分析及力学参数预测[J].岩土力学,2009,30(增刊1):195-200.WANG Suo,ZHAO Ming-jie,JIANG Shu-ping,et al.Analysis of tunnel rock damage evolution process in excavation and predicting mechanical parameters[J].Rock and Soil Mechanics,2009,30(Supp 1):195-200.
[11]何忠明,曹平.考虑应变软化的地下采场开挖变形稳定性分析[J].中南大学学报,2008,39(4):641-646.HE Zhong-ming,CAO Ping.Deformation and stability analysis of underground stope after excavation considering strain softening[J].Journal of Central South University,2008,39(4):641-646.
[12]周家文,徐卫亚,李明卫,等.岩石应变软化模型在深埋隧洞数值分析中的应用[J].岩石力学与工程学报,2009,28(6):1116-1127.ZHOU Jia-wen,XU Wei-ya,LI Ming-wei,et al.Application of rock strain softening model to numerical analysis of deep tunnel[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(6):1116-1127.
[13]李英杰,张顶立,刘保国.考虑变形模量劣化的应变软化模型在FLAC3D中的开发与验证[J].岩土力学,2011,32(增刊2):647-652.LI Ying-jie,ZHANG Ding-li,LIU Bao-guo.Development and verification of strain-softening model considering deformation modulus degradation in FLAC3D[J].Rock and Soil Mechanics,2011,32(Supp 2):647-652.
[14]卞康,肖明.二向不等围压条件下考虑软化及剪胀的圆形隧洞弹塑性解[J].岩石力学与工程学报,2011,30(增刊2):3831-3838.BIAN Kang,XIAO Ming.Analytical solutions of circular tunnel under two-dimensional unequal pressure considering dilatancy and softening[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(Supp 2):3831-3838.
[15]孙金山,卢文波.非轴对称荷载下圆形隧洞围岩弹塑性分析解析解[J].岩土力学,2007(增刊1):327-332.SUN Jin-shan,LU Wen-bo.Analytical elasto-plastic solutions to supporting rock masses of circular tunnels under asymmetric load[J].Rock and Soil Mechanics,2007,28(Supp 1):327-332.
[16]沈为.损伤力学[M].武汉:华中理工大学出版社,1995:9-10.
[17]周辉,张凯,冯夏庭,等.脆性大理岩弹塑性耦合力学模型研究[J].岩石力学与工程学报,2010,29(12):2398-2409.ZHOU Hui,ZHANG Kai,FENG Xia-ting,et al.Elastoplastic coupling mechanical model for brittle marble[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(12):2398-2409.
[18]王渭明,杨更社,张向东,等.岩石力学[M].徐州:中国矿业大学出版社,2010:166-167.
[2]李政林,吴瑞祥,李龙剑,等.基于损伤理论的隧道围岩松动圈确定方法[J].地下空间与工程学报,2011,7(6):1060-1064.LI Zheng-lin,WU Rui-xiang,LI Long-jian,et al.Method for defining the loose zone of tunnel surrounding rock based on damage theory[J].Chinese Journal of Underground Space and Engineering,2011,7(6):1060-1064.
[3]马青,赵均海,魏雪英,等.基于损伤理论的圆形隧洞围岩应力场分析[J].建筑科学与工程学报,2011,28(2):84-94.MA Qing,ZHAO Jun-hai,WEI Xue-ying,et al.Stress field analysis of circular tunnel surrounding rock based on damage theory[J].Journal of Architecture and Civil Engineering,2011,28(2):84-94.
[4]张强,王水林,葛修润.圆形巷道围岩应变软化弹塑性分析[J].岩石力学与工程学报,2010,29(5):1031-1035.ZHANG Qiang,WANG Shui-lin,GE Xiu-run.Elastoplastic anslysis of circular openings in strainsoftening rock masses[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(5):1031-1035.
[5]王水林,吴振君,李春光,等.应变软化模拟与圆形隧道衬砌分析[J].岩土力学,2010,31(6):1929-1936.WANG Shui-lin,WU Zhen-jun,LI Chun-guang,et al.Modeling of strain-softening and analysis of a lining for circular tunnel[J].Rock and Soil Mechanics,2010,31(6):1929-1936.
[6]张常光,徐飞,张庆贺,等.岩石隧道塑性位移新解[J].岩石力学与工程学报,2011,30(增刊2):3551-3556.ZHANG Chang-guang,XU Fei,ZHANG Qing-he,et al.New plastic solution for displacement of rock tunnels[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(Supp 2):3551-3556.
[7]蒋斌松,张强,贺永年,等.深部圆形巷道破裂围岩的弹塑性分析[J].岩石力学与工程学报,2007,26(5):982-986.JIANG Bin-song,ZHANG Qiang,HE Yong-nian,et al.Elasto-plastic analysis of cracked surrounding rocks in deep circular openings[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(5):982-986
[8]潘阳,赵光明,孟祥瑞.非均匀应力场下巷道围岩弹塑性分析[J].煤炭学报,2011,36(增刊1):53-57.PAN Yang,ZHAO Guang-ming,MENG Xiang-rui.Elasto-plastic analysis on surrounding rock mass under non-uniform stress field[J].Journal of China Coal Society,2011,36(Supp 1):53-57.
[9]陈立伟,彭建兵,范文,等.基于统一强度理论的非均匀应力场圆形巷道围岩塑性区分析[J].煤炭学报,2007,32(1):20-23.CHEN Li-wei,PENG Jian-bing,FAN Wen,et al.Analysis of surrounding rock mass plastic zone of round tunnel under non-uniform stress field based on the unified strength theory[J].Journal of China Coal Society,2007,32(1):20-23.
[10]王唢,赵明阶,蒋树屏,等.隧道开挖中围岩损伤演化分析及力学参数预测[J].岩土力学,2009,30(增刊1):195-200.WANG Suo,ZHAO Ming-jie,JIANG Shu-ping,et al.Analysis of tunnel rock damage evolution process in excavation and predicting mechanical parameters[J].Rock and Soil Mechanics,2009,30(Supp 1):195-200.
[11]何忠明,曹平.考虑应变软化的地下采场开挖变形稳定性分析[J].中南大学学报,2008,39(4):641-646.HE Zhong-ming,CAO Ping.Deformation and stability analysis of underground stope after excavation considering strain softening[J].Journal of Central South University,2008,39(4):641-646.
[12]周家文,徐卫亚,李明卫,等.岩石应变软化模型在深埋隧洞数值分析中的应用[J].岩石力学与工程学报,2009,28(6):1116-1127.ZHOU Jia-wen,XU Wei-ya,LI Ming-wei,et al.Application of rock strain softening model to numerical analysis of deep tunnel[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(6):1116-1127.
[13]李英杰,张顶立,刘保国.考虑变形模量劣化的应变软化模型在FLAC3D中的开发与验证[J].岩土力学,2011,32(增刊2):647-652.LI Ying-jie,ZHANG Ding-li,LIU Bao-guo.Development and verification of strain-softening model considering deformation modulus degradation in FLAC3D[J].Rock and Soil Mechanics,2011,32(Supp 2):647-652.
[14]卞康,肖明.二向不等围压条件下考虑软化及剪胀的圆形隧洞弹塑性解[J].岩石力学与工程学报,2011,30(增刊2):3831-3838.BIAN Kang,XIAO Ming.Analytical solutions of circular tunnel under two-dimensional unequal pressure considering dilatancy and softening[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(Supp 2):3831-3838.
[15]孙金山,卢文波.非轴对称荷载下圆形隧洞围岩弹塑性分析解析解[J].岩土力学,2007(增刊1):327-332.SUN Jin-shan,LU Wen-bo.Analytical elasto-plastic solutions to supporting rock masses of circular tunnels under asymmetric load[J].Rock and Soil Mechanics,2007,28(Supp 1):327-332.
[16]沈为.损伤力学[M].武汉:华中理工大学出版社,1995:9-10.
[17]周辉,张凯,冯夏庭,等.脆性大理岩弹塑性耦合力学模型研究[J].岩石力学与工程学报,2010,29(12):2398-2409.ZHOU Hui,ZHANG Kai,FENG Xia-ting,et al.Elastoplastic coupling mechanical model for brittle marble[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(12):2398-2409.
[18]王渭明,杨更社,张向东,等.岩石力学[M].徐州:中国矿业大学出版社,2010:166-167.