Shear Properties of Anisotropic Structural Surfaces with Similar Strength
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摘要: 为加深对异性结构面力学性质的认识,基于Barton标准剖面线制作了4种粗糙系数的石膏-砂浆结构面试样,两种材料的强度相近,在3种法向应力下进行室内直剪试验和数值模拟。根据得到的两类剪切变形曲线,并对强度相近异性结构面的峰值剪切强度随粗糙系数和法向应力增长而变化的规律及变形特征进行分析;依据数值模拟结果总结了强度相近异性结构面的剪切破坏模式。研究发现强度相近的异性结构面剪切存在如下特征:低粗糙系数结构面的剪切应力-位移曲线到达峰值后即进入残余变形阶段,而较高粗糙系数结构面的剪切应力-位移曲线存在明显的软化阶段;剪切应力增长得快慢与粗糙系数、法向应力正相关;在不同法向应力下,随粗糙系数的增大,先后发生爬坡破坏、爬坡-啃断破坏、啃断破坏。Abstract: To further understand the mechanical properties of anisotropic structural surfaces, the specimens with gypsum-mortar structural surfaces in four joint roughness coefficients were made based on the standard Barton’s section lines of structural surfaces. Particularly, gypsum and mortar had the similar uniaxial compressive strength. Two kinds of curves between shear stress and displacement were obtained by indoor direct shear tests under three kinds of normal stress. Consequently, the change laws for peak shear strength of specimens with gypsum-mortar structural surfaces with the increase of joint roughness coefficients and normal stress were analyzed. Based on the numerical simulating results, the shear failure modes of anisotropic structural surfaces with similar strength were summarized. The curves between shear stress and displacement of anisotropic structural surfacess with lower roughness coefficients developed to the residual deformation stage after reaching peak values, while the curves of specimens with higher roughness coefficients evolved to the obvious softening stage. The growth rates of shear stress was positively correlated with roughness coefficients and normal stress. Under different normal stress, climbing failure, climbing-gnawing failure and gnawing failure occured successively to the anisotropic structural surfaces with similar strength as the roughness coefficient increased.
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[1] 贺建明, 吴刚. 岩体异性结构面的抗剪强度准则[J]. 重庆大学学报, 1994, 17(2):105-110. [2] 刘小然, 周宏伟, 李洪. 岩石-混凝土相互作用力学行为的数值模拟研究[J]. 岩石力学与工程学报, 2005, 24(增刊2):5648-5651. [3] 易成, 王长军, 刘晋艳, 等. 两体接触面剪切力学行为的三维数值分析[J]. 岩土力学, 2008, 29(8):2149-2156. [4] YANG C X, JIANG Q, LI Y H, et al. Shearing performance of natural matched joints with different wall strengths under direct shearing tests[J]. Geotechnical Testing Journal, 2018, 41(2):371-389. [5] WU Q, XU Y J, TANG H M, et al. Peak shear strength prediction for discontinuities between two different rock types using a neural network approach[J]. Bulletin of Engineering Geology and the Environment, 2019, 78(4):2315-2329. [6] 何刘, 赵志明, 吴光, 等. 岩体结构面表面形态剪切弱化行为特征试验研究[J]. 岩土力学, 2020(增刊2):1-11. [7] KODIKARA J K, JOHNSTON I W. Shear behaviour of irregular triangular rock-concrete joints[J]. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1994, 31(4):313-322. [8] GHAZVINIAN A H, TAGHICHIAN A, HASHEMI M, et al. The shear behaviour of bedding planes of weakness between two different rock types with high strength difference[J]. Rock Mechanics and Rock Engineering, 2010, 43(1):69-87. [9] 方堃, 吴琼, 王姣, 等. 基于颗粒流异性层面剪切特性及演化机理研究[J]. 长江科学院院报, 2014, 31(11):31-37. [10] 张雅慧, 汪丁建, 唐辉明, 等. 基于PFC2D数值试验的异性结构面剪切强度特性研究[J]. 岩土力学, 2016, 37(4):1031-1041. [11] 范祥, 邓志颖, 崔志猛, 等. 一种新的软-硬节理峰值剪切强度模型[J]. 岩土力学, 2021, 42(7):1861-1870. [12] 黄胜. 高烈度地震下隧道破坏机制及抗震研究[D]. 武汉:中国科学院武汉岩土力学研究所, 2010. [13] 赵坤, 陈卫忠, 赵武胜, 等. 地下工程衬砌与减震层接触面力学特性直剪试验与数值仿真[J]. 岩土力学,2018, 39(7):2662-2670. [14] 张茂础, 盛谦, 崔臻, 等. 围岩-衬砌接触面剪切力学性质及破坏机制的试验研究[J]. 岩石力学与工程学报, 2020, 39(3):550-559. [15] 朱瑞娟, 顾琳琳. 规则齿形结构面剪切-渗流耦合特性[J]. 工业建筑, 2020, 50(10):101-105. [16] 冯鹏, 张汉青, 孟鑫淼, 等. 3D打印技术在工程建设中的应用及前景[J]. 工业建筑, 2019, 49(12):154-165,194. [17] BARTON N, CHOUBEY V. The shear strength of rock joints in theory and practice[J]. Rock Mechanics and Rock Engineering, 1978, 10(1/2):1-54. [18] 曹平, 何云, 范祥, 等. 剪切前后结构面表面形貌纹理特征变化[J]. 中南大学学报(自然科学版), 2013, 44(11):4624-4630. [19] 蔡美峰,何满朝,刘东燕. 岩石力学与工程[M]. 北京:科学出版社,2013.
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