Abstract
Bedding planes or layers can have a serious effect on the mechanical behaviour of shale rock. Fractures occurring along bedding planes form a fracture network in shale hydraulic fracturing; thus, the tensile strength and fracture mode are important for hydraulic fracturing design. In this research, shale disk specimens are prepared and analysed under Brazilian test conditions. During the test, a 3D digital image correlation system (DIC) is employed to capture surface deformation, and an AE sensor and strain observation system are, respectively, used to record the AE event and central strain of the shale disk during the failure process. A new inherently anisotropic model is established with a banded-particle model and smooth joint model using the particle flow code (PFC2D). The laboratory test result shows that the Brazilian tensile strength (BTS) value decreased gradually along with bedding inclination, which corresponds to a trend of the decrease of the strength over the entire interval, but it is a rather systematic decrease, approximating a linear variation. By considering the specimen after failure, three types of fracture patterns are observed: arc fracture (AF) through outside the central part, central fracture along the loading direction (LA) and mixed fracture patterns of the two. The DIC and central strain observation systems confirm that the split fractures do not always propagate along the diametrical loading direction, which means that the traditional isotropic elastic theory no longer works for layered shale. The micro-level failure behaviour and mechanism are analysed by PFC simulation. The PFC simulation reveals that the rock matrix tensile fracture and shear fracture along bedding plane are the main fracture pattern of shale disk specimens under the Brazilian test. The bedding inclination and interlayer bonding force play a very important role in the anisotropic behaviour of the shale.
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References
Bahaaddini M, Sharrock G, Hebblewhite B (2013) Numerical investigation of the effect of joint geometrical parameters on the mechanical properties of a non-persistent jointed rock mass under uniaxial compression. Comput Geotech 49:206–225
Berard T, Liu Q, Dubost FX, Jing B (2012) A screening process for shale gas prospecting. SPE Pap 154736:19
Chiu C, Wang TT, Wen MC, Huang TH (2013) Modeling the anisotropic behavior of jointed rock mass using a modified smooth-joint model. Int J Rock Mech Min Sci 62:14–22
Cho N, Martin CD, Sego DC (2007) A clumped particle model for rock. Int J Rock Mech Min Sci 44(7):997–1010
Cho JW, Kim H, Jeon S, Min KB (2012) Deformation and strength anisotropy of Asan gneiss, Boryeong shale, and Yeoncheon schist. Int J Rock Mech Min Sci. https://doi.org/10.1016/j.ijrmms.2011.12.004
Chu WJ, Zhang CS, Hou JA (2013) Particle-based model for studying anisotropic strength and deformation of schist. In: Proceedings of the 3rd ISRM SINOROCK symposium. Shanghai, China, pp 593–96
Cundall PA (1971) A computer model for simulating progressive large scale movements in blocky rock systems. In: Proceedings of the symposium of International Society of Rock Mechanics, vol. 1, Nancy: France, paper no. II-8
Cundall PA (2001) Discontinuous future for numerical modelling in geomechanics? Proc ICE Geotech Eng 149:41–47
Dan DQ, Konietzky H (2014) Numerical simulations and interpretations of Brazilian tensile tests on transversely isotropic rocks. Int J Rock Mech Min Sci 71(4):53–63
Debecker B, Vervoort A (2009) Experimental observation of fracture patterns in layered slate. Int J Fract 159(1):51–62
Duan K, Kwok CY (2015) Discrete element modeling of anisotropic rock under Brazilian test conditions. Int J Rock Mech Min Sci 78:46–56
Duan K, Kwok CY, Pierce M (2016) Discrete element method modeling of inherently anisotropic rocks under uniaxial compression loading. Int J Numer Anal Meth Geomech 40(8):1150–1183
Hakala M, Kuula H, Hudson JA (2007) Estimating the transversely isotropic elastic intact rock properties for in situ stress measurement data reduction: a case study of the Olkiluoto mica gneiss, Finland. Int J Rock Mech Min Sci 44:14–46
He J, Afolagboye LO (2018) Influence of layer orientation and interlayer bonding force on the mechanical behavior of shale under Brazilian test conditions. Acta Mech Sin 34(2):349–358
Heng S, Guo Y, Yang C, Daemen JJK, Li Z (2015) Experimental and theoretical study of the anisotropic properties of shale. Int J Rock Mech Min Sci 74(1):58–68
Itasca Consulting Group Inc (2008) Particle flow code in 2 dimensions. Version 4.0. Itasca Consulting Group Inc, Minneapolis
Josh M, Esteban L, Piane CD, Sarout J, Dewhurst DN, Clennell MB (2012) Laboratory characterisation of shale properties. J Petrol Sci Eng 88–89(2):107–124
Kim H, Cho JW, Song I, Min KB (2012) Anisotropy of elastic moduli, p-wave velocities, and thermal conductivities of Asan gneiss, Boryeong shale, and Yeoncheon schist in Korea. Eng Geol 147–148(5):68–77
Kuila U, Dewhurst DN, Siggins AF, Raven MD (2011) Stress anisotropy and velocity anisotropy in low porosity shale. Tectonophysics 503(1–2):34–44
Li X, Lei X, Li Q, Li X (2017) Experimental investigation of sinian shale rock under triaxial stress monitored by ultrasonic transmission and acoustic emission. J Nat Gas Sci Eng 43:110–123
Masri M, Sibai M, Shao JF, Mainguy M (2014) Experimental investigation of the effect of temperature on the mechanical behavior of Tournemire shale. Int J Rock Mech Min Sci 70(9):185–191
Nasseri MH, Rao KS, Ramamurthy T (1997) Failure mechanism in schistose rocks. Int J Rock Mech Min Sci 34(3–4):219
Nasseri MH, Rao KS, Ramamurthy T (2003) Anisotropic strength and deformational behavior of Himalayan schists. Int J Rock Mech Min Sci 40:3–23
Niandou H, Shao JF, Henry JP, Fourmaintraux D (1997) Laboratory investigation of the mechanical behavior of Tournemire shale. Int J Rock Mech Min Sci 34(1):3–16
Park B, Min KB (2012) Discrete element modeling of shale as a transversely isotropic rock. In: Proceedings of 7th Asian rock mechanics symposium. Seoul, Korea, pp 336–342
Park B, Min KB (2013) Discrete element modeling of transversely isotropic rock. In: Proceedings of 47th US rock mechanics symposium. San Francisco, US, Paper ARMA13-490
Park B, Min KB (2015) Bonded-particle discrete element modeling of mechanical behavior of transversely isotropic rock. Int J Rock Mech Min Sci 76:243–255
Rybacki E, Reinicke A, Meier T, Makasi M, Dresen G (2015) What controls the mechanical properties of shale rocks?—part I: strength and Young’s modulus. J Petrol Sci Eng 135:702–722
Rybacki E, Meier T, Dresen G (2016) What controls the mechanical properties of shale rocks?—part II: brittleness. J Petrol Sci Eng 144:39–58
Tan X, Konietzky H, Fruhwirt T, Dan DQ (2015) Brazilian tests on transversely isotropic rocks: laboratory testing and numerical simulations. Rock Mech Rock Eng 48:1341–1351
Tavallali A, Vervoort A (2010a) Effect of layer orientation on the failure of layered sandstone under Brazilian test conditions. Int J Rock Mech Min Sci 47:313–322
Tavallali A, Vervoort A (2010b) Failure of layered sandstone under brazilian test conditions: effect of micro-scale parameters on macro-scale behaviour. Rock Mech Rock Eng 43:641–653
Tavallali A, Vervoort A (2013) Behaviour of layered sandstone under Brazilian test conditions: layer orientation and shape effects. J Rock Mech Geotech Eng 5:366–377
Ulusay R (ed) (2014) The ISRM suggested methods for rock characterization, testing and monitoring: 2007–2014. Springer
Vervoort A, Min KB, Konietzky H, Cho JW et al (2014) Failure of transversely isotropic rock under Brazilian test conditions. Int J Rock Mech Min Sci 70:343–352
Wang FP, Gale JFW (2009) Screeing criteria for shale-gas systems. Gulf Coast Ass Geol Soc Trans 59:779–793
Wang J, Xie L, Xie H, Ren L, He B, Li C et al (2016a) Effect of layer orientation on acoustic emission characteristics of anisotropic shale in Brazilian tests. J Nat Gas Sci Eng 36:1120–1129
Wang T, Xu DP, Elsworth D, Zhou WB (2016b) Distinct element modeling of strength variation in jointed rock masses under uniaxial compression. Geomech Geophys Geo-energy Geo-resour 2:11–24
Wu S, Ge H, Wang X, Meng F (2017) Shale failure processes and spatial distribution of fractures obtained by ae monitoring. J Nat Gas Sci Eng 41:82–92
Yang SQ, Huang YH (2014) Particle flow study on strength and meso-mechanism of Brazilian splitting test for jointed rock mass. Acta Mech Sin 30(4):547–558
Yang SQ, Huang YH, Jing HW, Liu XR (2014) Discrete element modeling on fracture coalescence behavior of red sandstone containing two unparallel fissures under uniaxial compression. Eng Geol 178:28–48
Yang SQ, Tian WL, Huang YH (2018) Failure mechanical behavior of pre-holed granite specimens after elevated temperature treatment by particle flow code. Geothermics 72:124–137
Yang SQ, Tian WL, Jing HW, Huang YH, Yang XX, Meng B (2019) Deformation and damage failure behavior of mudstone specimens under single-stage and multi-stage triaxial compression. Rock Mech Rock Eng 52(3):673–689
Yin PF, Yang SQ (2018) Experimental investigation of the strength and failure behavior of layered sandstone under uniaxial compression and Brazilian testing. Acta Geophys 4(66):585–605
Acknowledgements
This research was supported by the Fundamental Research Funds for the Central Universities (2015XKZD05) and Six Talents Peak Project in Jiangsu Province (JNHB-090). The authors would also like to express their sincere gratitude to the editor and two anonymous reviewers for their valuable comments which have greatly improved this paper.
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Yang, SQ., Yin, PF. & Huang, YH. Experiment and Discrete Element Modelling on Strength, Deformation and Failure Behaviour of Shale Under Brazilian Compression. Rock Mech Rock Eng 52, 4339–4359 (2019). https://doi.org/10.1007/s00603-019-01847-z
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DOI: https://doi.org/10.1007/s00603-019-01847-z