岩体的强度主要由结构面控制,为确定结构面对隧洞围岩的影响,在对围岩中单一结构面的应力分布和破坏形式进行理论分析的基础上,研究了结构面倾角以及结构面到隧洞中心的距离对节理围岩破坏机理的影响。并利用3DEC离散元程序分别对不同结构面分布、不同岩石强度和结构面强度下18种组合的围岩变形进行了计算,分析了结构面不同分布情况下围岩的破坏模式;对比分析岩石、结构面强度不同组合下岩石强度和变形特征,研究了结构面力学变形性质在岩体损伤破坏中的贡献。研究结果表明:结构面距开挖轮廓线越近越容易发生破坏;结构面倾角影响结构面首先发生破坏的位置;结构面的分布决定围岩首先发生破坏的位置,结构面的破坏不一定会导致围岩的破坏。研究成果对不同结构面组合分布的围岩变形和破坏分析具有一定的指导意义。
Abstract
The strength of rock mass is controlled by structural plane. On the basis of theoretical analysis on stress distribution and failure mechanism of single structural plane in surrounding rock, the influences of dip angle of structural plane and distance from structural plane to tunnel center on the failure mechanism of jointed rock mass are researched. The results are concluded as follows: 1) discontinuities are more likely to occur when structural plane is closer to the excavation contour line; 2) the position where structural plane first destructs is affected by the angle of structural plane. Furthermore, the deformation of 18 groups of rock masses with different combinations of discontinuity distribution, rock strength and discontinuity strength are calculated and compared in three-dimensional element code (3DEC), and the failure mechanisms of surrounding rock with various discontinuities distribution are analyzed. The contribution of structural plane’s mechanical properties to rock failure is also studied: the distribution of structural plane determines the location of the first failure; and the failure of structural plane does not necessarily lead to the failure of surrounding rock.
关键词
深部隧洞 /
节理围岩 /
结构面 /
几何参数 /
离散元 /
破坏机理
Key words
deep tunnel /
jointed surrounding rock /
discontinuities /
geometric parameters /
discrete element /
failure mechanism
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参考文献
[1] JAEGER J, COOK N. Fundamentals of Rock Mechanics[M]. London:Chapman and Hall Ltd.,1969:53-108.
[2] RAMAMURTHY T, ARORA V K. Strength Predictions for Jointed Rocks in Confined and Unconfined States[J]. International Journal of Rock mechanics and Mining Sciences & Geomechanics Abstracts,1994,31(1):9-22.
[3] REYES O,EINSTEIN H H. Failure Mechanisms of Fractured Rock—A Fracture Coalescence Model[C]∥Proceedings of 7th International Congress on Rock Mechanics. USA:A. A. Balkema Publishers,1991:333-340.
[4] 梁正召,肖东坤,李聪聪,等. 断续节理岩体强度与破坏特征的数值模拟研究[J]. 岩土工程学报,2014,36(11):2086-2095.
[5] 孟国涛,方 丹,李良权,等. 含优势断续节理组的工程岩体等效遍布节理模型强度参数研究[J]. 岩石力学与工程学报,2013,32(10):2115-2121.
[6] 范景伟,何江达. 含定向闭合断续节理岩体的强度特性[J]. 岩石力学与工程学报,1992,11(2):190-199.
[7] 张 建,赵建平. 上覆土层节理岩质边坡稳定性数值分析[J]. 长江科学院院报,2015,32(2):108-113.
[8] 刘 勇,王运生,唐 起. 不同地质条件下边坡动力特征的DDA方法分析[J]. 长江科学院院报,2016,33(7):115-120.
[9] ZHANG X L,JIAO Y Y,ZHAO J. Simulation of Failure Process of Jointed Rock[J]. Journal of Central South University of Technology,2008,15(6):888-894.
[10]包 磊,陈春武,潘 昆,等. 记忆离散元的节理岩体水工隧洞地震动力特征分析[J]. 长江科学院院报,2015,32(10):78-84.
[11]SHREEDHARAN S,KULATILAKE P H S W. Discontinuum-Equivalent Continuum Analysis of the Stability of Tunnels in a Deep Coal Mine Using the Distinct Element Method[J]. Rock Mechanics and Rock Engineering,2016,49(5):1903-1922.
[12]王 帅,唐爱松,熊诗湖,等. 节理岩体大型地下洞室群开挖支护过程离散元分析[J]. 长江科学院院报,2014,31(11):131-135.
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