Effect of normal stress on the shear leading edge of sandstone rock joint
HUANG Man1, 2, 3, XU Sheng1, 2, 3, WENG Hanqian4, HONG Chenjie1, 2, 3*, TAO Zhigang4, ZHANG He1, 2, 3
(1. State Key Laboratory of Intelligent Deep Metal Mining and Equipment, Shaoxing University, Shaoxing, Zhejiang 312000, China; 2. School of Civil Engineering, Shaoxing University, Shaoxing, Zhejiang 312000, China; 3. Zhejiang Key Laboratory of Rock Mechanics and Geohazards, Shaoxing University, Shaoxing, Zhejiang 312000, China; 4. State Key Laboratory of Tunnel Engineering,
China University of Mining and Technology (Beijing), Beijing 100083, China)
Abstract：The closure behavior of rock joints significantly influences their shear mechanics. This study employs pressure-sensitive films to measure three groups of sandstone joints, discussing the relationship between effective contact characteristics and shear strength. The results indicate that: (1) Under identical normal stress, the effective contact area ratio varies with different shear directions. As normal stress increases, the effective contact area ratio exhibits a linear growth trend, ultimately reaching approximately 50% of the actual contact area ratio. (2) Variations in effective average contact stress also show significant differences across shear directions. Additionally, the rougher the joint surface, the more pronounced the fluctuations in effective average contact stress. Furthermore, the average effective dip angle decreases following a negative exponential trend as normal stress increases, gradually approaching a stable value indicative of a fully contacted state. (3) An effective roughness indicator, which accounts for the influence of normal stress, is modified based on the effective contact area ratio. Building on this, a new peak shear strength model for rock joints is developed using the Barton criterion. This model satisfies boundary condition constraints, and its accuracy in predicting the peak shear strength of rock joints has been validated through direct shear tests and comparisons with several published datasets. These findings provide a theoretical foundation for understanding the shear mechanisms of sandstone joints.
[1] 杜时贵. 岩体结构面的工程性质[M]. 北京：地震出版社，1999：78–81.(DU Shigui. Engineering properties of jointed rock mass[M]. Beijing：Seismological Press，1999：78–81.(in Chinese))
[2] 夏才初，孙宗颀. 工程岩体节理力学[M]. 上海：同济大学出版社，2002：94–107.(XIA Caichu，SUN Zongqi. Engineering jointed rock mass mechanics[M]. Shanghai：Tongji University Press，2002：94–107.(in Chinese))
[3] 钟 振，陈致远，胡云进，等. 变剪切速度下粗糙岩石节理剪切强度演化规律及失稳判据[J]. 岩石力学与工程学报，2025，44(10)：2 592–2 607.(ZHONG Zhen，CHEN Zhiyuan，HU Yunjin，et al. Shear strength evolution and instability criterion of rough rock joint under variable shear rates[J]. Chinese Journal of Rock Mechanics and Engineering，2025，44(10)：2 592–2 607.(in Chinese))
[4] ZHAO J. Joint surface matching and shear strength part A：Joint matching coefficient (JMC)[J]. International Journal of Rock Mechanics and Mining Science，1997，34(2)：173–178.
[5] LI B，ZHAO Z H，JANG Y J，et al. Contact mechanism of a rock fracture subjected to normal loading and its impact on fast closure behavior during initial stage of fluid flow experiment[J]. International Journal for Numerical and Analytical Methods in Geomechanics，2015，39(13)：1 431–1 449.
[6] 王思维，李建春. 节理接触面积比对压缩波传播影响的动光弹实验研究[J]. 岩石力学与工程学报，2021，40(5)：939–947.(WANG Siwei, LI Jianchun. Dyamic photoelastic experimental study on the influence of joint contact area ratio on stress wave propagation[J]. Chinese Journal of Rock Mechanics and Engineering，2021，40(5)：939–947.(in Chinese))
[7] OZTURK H，KOCAMAN S，GOKCEOGLU C. A low-cost approach for determination of discontinuity orientation using smartphone images and application to a part of Ihlara Valley[J]. Engineering Geology，2019，254：63–75.
[8] HERTZ H. Über die Berührung fester elastischer Körper[J]. Journal für die reine und angewandte Mathematik，1881，92：156–171.
[9] PYRAK-NOLTE L J，MYER L R，COOK N G W，et al. Hydraulic and mechanical properties of natural fractures in low permeability rock[C]// ISRM Congress. [S. l.]：[s. n.]，1987：225–231.
[10] LOGAN J M，TEUFEL L W. The effect of normal stress on the real area of contact during frictional sliding in rocks[J]. Pure and Applied Geophysics，1986，124：471–485.
[11] RE F，SCAVIA C，ZANINETTI A. Variation in contact areas of rock joint surfaces as a function of scale[J]. International Journal of Rock Mechanics and Mining Sciences，1997，34(3/4)：254.e1–254.e12.
[12] XIA C，SHI Z，LI B，et al. A discontinuous smooth particle hydrodynamics method for modeling deformation and failure processes of fractured rocks [J]. Journal of Rock Mechanics and Geotechnical Engineering，2025，17(2)：705–721.
[13] NEMOTO K，WATANABE N，HIRANO N，et al. Direct measurement of contact area and stress dependence of anisotropic flow through rock fracture with heterogeneous aperture distribution[J]. Earth and Planetary Science Letters，2009，281(1/2)：81–87.
[14] SELVADURAI P A，GLASER S D. Experimental evidence of micromechanical processes that control localization of shear rupture nucleation[J]. Journal of Chongqing Technology and Business University，2013，577：117252.
[15] GIWELLI A A，SAKAGUCHI K，GUMATI A. Shear behavior of fractured rock as a function of size and shear displacement[J]. Geomechanics and Geoengineering，2014，9(4)：253–264.
[16] MA H，CAO Y，QIAN J，et al. Theoretical study of the mesoscopic mechanism of rock fractures during normal deformation[J]. Rock Mechanics and Rock Engineering，2023，56(8)：5 719–5 733.
[17] GONG G，XIONG F，SHEN L，et al. Fractal contact and asperities coalescence of rock joints under normal loading：Insights from pressure-sensitive film measurement[J]. International Journal of Rock Mechanics and Mining Sciences，2024，183：105908.
[18] LI Y，CUI Y，LI Y，et al. Analysis and prediction of contact characteristics of rock fracture surfaces under normal loading[J]. Journal of Structural Geology，2024，180：105086.
[19] 李育宗，张 讴，崔浩翔，等. 不同岩性和错动位移条件下岩体结构面的真实接触面积[J]. 岩石力学与工程学报，2025，44(11)：2 901–2 919.(LI Yuzong，ZHANG Ou，CUI Haoxiang，et al. Real contact area of rock discontinuities：lithological variations and offset displacements[J]. Chinese Journal of Rock Mechanics and Engineering，2025，44(11)：2 901–2 919.(in Chinese))
[20] TANG Z C，HUANG R Q，LIU Q S，et al. Effect of contact state on the shear behavior of artificial rock joint[J]. Bulletin of Engineering Geology and the Environment，2016，75(2)：761–769.
[21] 班力壬，候宇航，杜伟升，等. 考虑实际接触节理微凸体对剪切强度不同贡献比例的峰值剪胀角模型[J]. 煤炭学报，2023，48(10)：3 688–3 699.(BAN Liren，HOU Yuhang，DU Weisheng，et al. A new peak dilation angle model for rock joints considering different contribution proportions of actual contact joint asperities to shear strength[J]. Journal of China Coal Society，2023，48(10)：3 688–3 699.(in Chinese))
[22] BARTON N. Review of a new shear-strength criterion for rock joints[J]. Engineering Geology，1973，7(4)：287–332.
[23] GRASSELLI G，WIRTH J，EGGER P. Quantitative three-dimensional description of a rough surface and parameter evolution with shearing[J]. International Journal of Rock Mechanics and Mining Sciences，2002，39(6)：789–800.
[24] GRASSELLI G，EGGER P. Constitutive law for the shear strength of rock joints based on three-dimensional surface parameters[J]. International Journal of Rock Mechanics and Mining Sciences，2003，40(1)：25–40.
[25] XIA C，TANG Z，TANG W，et al. New peak shear strength criterion of rock joints based on quantified surface description[J]. Rock Mechanics and Rock Engineering，2014，47(2)：387–400.
[26] TIAN Y，LIU Q，MA H，et al. New peak shear strength model for cement filled rock joints[J]. Engineering Geology，2017，233(1)：269–290.
[27] 陈 曦，曾亚武，孙翰卿，等. 基于Grasselli形貌参数的岩石节理初始剪胀角新模型[J]. 岩石力学与工程学报，2019，38(1)：133–152.(CHEN Xi，ZENG Yawu，SUN Hanqin，et al. A new model of the initial dilatancy angle of rock joints based on Grasselli?s morphological parameters[J]. Chinese Journal of Rock Mechanics and Engineering，2019，38(1)：133–152.(in Chinese))
[28] BAN L，DU W，QI C. A peak dilation angle model considering the real contact area for rock joints[J]. Rock Mechanics and Rock Engineering，2020，53(11)：4 909–4 923.
[29] LI Y. Discussion on “A peak dilation angle model considering the real contact area for rock joints”[J]. Rock Mechanics and Rock Engineering，2021，54(1)：5 965–5 968.
[30] BARTON N，CHOUBEY V. The shear strength of rock joints in theory and practice[J]. Rock Mechanics，1977，10：1–54.
[31] ISRM. International society for rock mechanics commission on standardization of laboratory and field tests：Suggested method for the quantitative description of discontinuities in rock masses[J]. International Journal of Rock Mechanics and Mining Sciences，1978，15(6)：319–368.
[32] BRADLEY D，ROTH G. Adaptive thresholding using the integral image[J]. Journal of Graphics Tools，2007，12(2)：13–21.
[33] MANOGHARAN P，WOOD C，MARONE C，et al. Experimental investigation of elastodynamic nonlinear response of dry intact，fractured and saturated rock[J]. Rock Mechanics and Rock Engineering，2022，55(5)：2 665–2 678.
[34] SELVADURAI P A，GLASER S D. Laboratory developed contact models controlling instability on frictional faults：Foreshocks on frictional faults[J]. Journal of Geophysical Research: Solid Earth，2015，120(6)：4 208–4 236.
[35] 黄 曼，陈嘉龙，翁寒倩，等. 硬性结构面剪切全过程形貌接触演化特征研究[J]. 岩石力学与工程学报，2025，44(8)：2 029–2 039. (HUANG Man，CHEN Jialong，WENG Hanqian，et al. Study on the contact evolution of hard joint surface morphology during shearing process[J]. Chinese Journal of Rock Mechanics and Engineering，2025，44(8)：2 029–2 039.(in Chinese))
[36] 龚 耕，潘 佳，赵立春，等. 基于压敏胶片的法向应力作用下砂岩节理的接触特征研究[J]. 岩土力学，2024，45(10)：2 907–2 918.(GONG Geng，PAN Jia，ZHAO Lichun，et al. Investigation of the contact characteristics of sandstone rock joint under normal stress using the pressure-sensitive film[J]. Rock and Soil Mechanics，2024，45(10)：2 907–2 918.(in Chinese))
[37] TATONE B S A，GRASSELLI G. A method to evaluate the three-dimensional roughness of fracture surfaces in brittle geomaterials[J]. The Review of Scientific Instruments，2009，80(12)：125110.
[38] LIU Q，TIAN Y，LIU D，et al. Updates to JRC-JCS model for estimating the peak shear strength of rock joints based on quantified surface description[J]. Engineering Geology，2017，228：282–300.
[39] YANG J，GUAN R，DI H，et al. Experimental study on peak shear strength criterion for rock joints[J]. Rock Mechanics and Rock Engineering，2016，49(3)：821–835.
[40] 杜时贵，吕原君，罗战友，等. 岩体结构面抗剪强度尺寸效应联合试验系统及初级应用研究[J]. 岩石力学与工程学报，2021，40(7)：1 337–1 349.(DU Shigui，LV Yuanjun，LUO Zhanyou，et al. Combined test system for size effect of rock joint shear strength and its primary application research[J]. Chinese Journal of Rock Mechanics and Engineering，2021，40(7)：1 337–1 349.(in Chinese))
[41] MURALHA J，GRASSELLI G，TATONE B S A，et al. ISRM suggested method for laboratory determination of the shear strength of rock joints：revised version[J]. Rock Mechanics and Rock Engineering，2014，47(1)：291–302.
[42] DU W，BAN L，PENG L，et al. A peak shear displacement model considering three-dimensional roughness of the actual contact joint surface[J]. International Journal of Geomechanics，2023，23(10)：04023172.
[43] BAN L，DU W，ZHANG D，et al. Velocity-dependent effect on the peak shear strength of rock joints considering the distribution characteristics of contact joint surface[J]. Rock Mechanics and Rock Engineering，2024，57：2 523–2 537.
[44] JU Y，WAN C，REN Z，et al. Quantification of continuous evolution of full-field stress associated with shear deformation of faults using three-dimensional printing and phase-shifting methods[J]. International Journal of Rock Mechanics and Mining Sciences，2020，126：104187.
[45] ZHU S，ZHENG J，ZHU Z，et al. Experiments on three-dimensional flaw dynamic evolution of transparent rock-like material under osmotic pressure[J]. Tunnelling and Underground Space Technology，2022，128：104624.
2026, Vol. 45 
