Abstract：Based on the continuum theory, quantitative GSI rock rating system and Hoek-Brown strength criterion and by using the FLAC3D program as the development platform, the conventional plastic model and strain-softening model are adopted to comparatively analyze the spatial excavation surface effect curves of deep rock. Combined with engineering design and field applications of deep shaft support, numerical validation is performed. The equivalent strain softening model for jointed soft rock reflecting attenuation of the post-peak strength parameters shows that: the post-peak behaviors of rock mass are dominated by quality grade and confining pressure, and during unloading after the peak, the process of softening parameter is not a constant value and varies with the size of the confining pressure. By computing the excavation face spatial constraint response curves of deep soft rock, the calculated results based on Mohr-Coulomb and Hoek-Brown criterion ideal elastoplastic models are basically the same. The results of the elastoplastic model are quite different from those of the strain-softening model, mainly in the middle range of geological indices. Practical application shows that the equivalent strain softening model for jointed rock more truly reflects the post-peak mechanical behaviors of the deep soft rock, and furthermore, the link between the geological strength indices and the continuum theory is established for engineering applications so as to provide a reference for similar projects.
孙闯, 张向东, 李永靖. 深部软弱岩体峰后等效力学模型及数值计算研究[J]. 岩土工程学报, 2014, 36(6): 1113-1121.
SUN Chuang, ZHANG Xiang-dong, LI Yong-jing. Equivalent mechanical model for post-peak behaviors of deep soft rock and numerical computation. Chinese J. Geot. Eng., 2014, 36(6): 1113-1121.
[1] 袁亮. 深井巷道围岩控制理论及淮南矿区工程实践[M].北京: 煤炭工业出版社, 2006. (YUAN Liang. Control of surrounding strata in deep mine roadway and practice in Huainan area[M]. Beijing: China Coal Industry Publishing House, 2006. (in Chinese)) [2] 康红普, 林健, 杨景贺, 等. 松软破碎硐室群围岩应力分布及综合加固技术[J]. 岩土工程学报, 2011, 33(5): 808-815. (KANG Hong-pu, LIN Jian, YANG Jing-he, et al. Stress distribution and synthetic reinforcing technology for chamber group with soft and fractured surrounding rock[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(5): 808-815. (in Chinese)) [3] LEE Y K, PIETRUSZCZAK S. A new numerical procedure for elasto-plastic analysis of a circular opening excavated in a strain-softening rock mass[J]. Tunnelling and Underground Space Technology, 2008, 23(3): 588-599. [4] 张立松, 闫相祯, 杨恒林, 等. 基于测井信息的煤岩GSI-JP破碎分级预测[J]. 岩土工程学报, 2011, 33(7): 1091-1098. (ZHANG Li-song, YAN Xiang-zhen, YANG Heng-lin, et al. GSI-JP crushed classification prediction method of coal rock based on logging information[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(7): 1091-1098. (in Chinese)) [5] 孙闯, 张向东, 张建俊. 深部断层破碎带竖井围岩与支护系统稳定性分析[J]. 煤炭学报, 2013, 38(4): 587-595. (SUN Chuang, ZHANG Xiang-dong, ZHANG Jian-jun. Stability analysis of vertical shaft surrounding rock and supporting system in deep fault fracture[J]. Journal of China Coal Society, 2013, 38(4): 587-595. (in Chinese)) [6] 李英杰, 潘一山, 李忠华. 岩体产生分区碎裂化现象机理分析[J]. 岩土工程学报, 2006, 28(9): 1124-1129. (LI Ying-jie, PAN Yi-shan, LI Zhong-hua. Analysis of mechanism of zonal disintegration of rocks[J]. Chinese Journal of Geotechnical Engineering, 2006, 28(9): 1124-1129. (in Chinese)) [7] 夏才初, 唐志成, 宋英龙, 等. 节理峰值剪切位移及其影响因素分析[J]. 岩土力学, 2012, 33(4): 961-971. (XIA Cai-chu,TANG Zhi-cheng,et al. SONG Ying-longAnalysis of relationship between joint peak shear displacement and its influence factors[J]. Rock and Soil Mechanics, 2012, 33(4): 961-971. (in Chinese)) [8] ZDENEK P, BAZANT F. Continuum theory for strain- softening[J]. Journal of Engineering Mechanics, 1984, 110(12): 1666-1692. [9] 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): 1929-1937. (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): 1929-1937. (in Chinese)) [10] CAI M, KAISERA P K, UNOB H, et al. Estimation of rock mass deformation modulus and strength of jointed hard rock masses using the GSI system[J]. International Journal of Rock Mechanics & Mining Sciences, 2004, 41: 3-19. [11] HOEK E, BROWN E T. Practical estimates of rock mass strength[J]. International Journal of Rock Mechanics and Mining Sciences, 1997, 34(8): 1165-86. [12] CAI M, KAISERA P K, UNOB H, et al. Determination of residual strength parameters of jointed rock masses using the GSI system[J]. International Journal of Rock Mechanics & Mining Sciences, 2007, 44: 247-265. [13] ALEJANO L R, Alfonso Rodr guez-Dono, María Veiga. Plastic radii and longitudinal deformation profiles of tunnels excavatedin strain-softening rock masses[J]. Tunnelling and Underground Space Technology, 2012, 30: 169-182. [14] ZHAO X G, CAI M. A dilation angle model for rocks[J]. International Journal of Rock Mechanics and Mining Sciences, 2010, 47(3): 368-384. [15] HOEK E, CARRANZA-TORRES C, CORKUM B. Hoek-Brown failure criterion(2002 edition) [C]// Proceedings of NARMS-TAC 2002, Mining Innovation an Technology. Toronto: University of Toronto, 2002: 267-273. [16] ALEJANO L R, RODRIGUEZ-DONO A, VEIGA M. Plastic radii and longitudinal deformation profiles of tunnels excavatedin strain-softening rock masses[J]. Tunnelling and Underground Space Technology, 2012, 30: 169-182. [17] 孙闯, 张向东, 李永靖. 高应力软岩巷道围岩与支护结构相互作用分析[J]. 岩土力学, 2013, 34(9): 2601-2609. (SUN Chuang, ZHANG Xiang-dong, LI Yong-jing. Analysis of interaction between surrounding rock and support under high stressed soft rock roadway[J]. Rock and Soil Mechanics, 2013, 34(9): 2601-2609. (in Chinese)) [18] HOEK E, DIEDERICH M S. Empirical estimation of rock mass modulus[J]. Rock Mechanics and Rock Engineering, 2006: 203-215. [19] 侯公羽, 李晶晶. 弹塑性变形条件下围岩-支护相互作用全过程解析[J]. 岩土力学, 2012, 33(4): 961-971. (HOU Gong-yu, LI Jing-jing. Analysis of complete process of interaction of surrounding rock and support under elastioplastic deformation condition[J]. Rock and Soil Mechanics, 2012, 33(4): 961-971. (in Chinese)) [20] CARRANZA-TORRES C, FAIRHURST C. Application of convergence-confinement method of tunnel design to rock masses that satisfy the Hoek-Brown failure criterion. Tunnelling and Underground Space Technology, 2009, 15(2): 187-213. [21] 赵星光, 蔡明, 蔡美峰. 岩石剪胀角模型与验证[J]. 岩石力学与工程学报, 2010, 29(5): 970-982. (ZHAO Xing-guang, CAI Ming, CAI Mei-feng. A rock dilation angle model and its verification[J]. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(5): 970-982. (in Chinese)) [22] ALEJANO L R, ALONSO E. Application of the convergence-confinement method to tunnels in rock masses exhibiting Hoek-Brown strain-softening behaviour[J]. International Journal of Rock Mechanics and Mining Sciences, 2010, 47(1): 150-160. [23] 张传庆, 冯夏庭, 周辉, 等. 应力释放法在隧洞开挖模拟中若干问题的研究[J]. 岩土力学, 2008, 29(5): 1174-1181. (ZHANG Chuan-qing, FENG Xia-ting, ZHOU Hui, et al. Study of some problems about application of stress release method to tunnel excavation simulation[J]. Rock and Soil Mechanics, 2008, 29(5): 1174-1181. (in Chinese))
