Abstract
The weak bedding sandwiched between rock layers is one of the crucial factors influencing the overburden failure with the extraction of coal resources in longwall mining. In this article, the physical model tests and discrete element modelling (DEM) were carried out to examine the effects of bedding adhesion strength (BAS) on the roof fracture with longwall coal mining. A novel model generation method in the universal distinct element code was proposed for the investigation of a propagating crack interaction with existing discontinuities. It is found that crack trajectory changes from deflection to penetration with the strength increase of a discontinuity. The stair-stepping fracture of overburden cantilever structure is more prominent for the rock layers with weaker BAS, which is in coincidence with the triangular block-based DEM result. Moreover, the mechanism of failure pattern influenced by BAS was clarified by the cantilever beam theory and fracture criterion of crack competition. With the outcomes above, the longwall coal mining-induced stratified roof fracture characteristics in engineering scale were revealed. Three quantitative regions were divided in terms of the strength ratio between bedding and rock layer. Finally, three aspects, the heights of the caved zone and fractured zone, the subsidence of ground surface, and the abutment pressure of roof affected by the BAS were discussed, respectively, with some suggestions recommended for the stability controlling of roof and safety production of coal mining.
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Alneasan M, Behnia M, Bagherpour R (2019) Analytical investigations of interface crack growth between two dissimilar rock layers under compression and tension. Eng Geol 259:105188
Brady BH, Brown ET (2004) Rock mechanics: for underground mining. Springer, New York
Burbaum U, Sass I (2017) Physics of adhesion of soils to solid surfaces. Bull Eng Geol Env 76:1097–1105
Cai J, Zhao J (2000) Effects of multiple parallel fractures on apparent attenuation of stress waves in rock masses. Int J Rock Mech Min Sci 37:661–682
Casberg CH, Spencer WH (1929) Investigation of endurance of bond strength of various clays in molding sand. University of Illinois at Urbana Champaign, College of Engineering, Champaign
Coggan J, Gao F, Stead D, Elmo D (2012) Numerical modelling of the effects of weak immediate roof lithology on coal mine roadway stability. Int J Coal Geol 90–91:100–109. https://doi.org/10.1016/j.coal.2011.11.003
Cook J, Gordon J (1964) A mechanism for the control of crack propagation in all-brittle systems. Proc R Soc Lond Ser A Math Phys Sci 282:508–520
Duan S-Q, Feng X-T, Jiang Q, Liu G-F, Pei S-F, Fan Y-L (2017) Situ observation of failure mechanisms controlled by rock masses with weak interlayer zones in large underground cavern excavations under high geostress. Rock Mech Rock Eng 50:2465–2493. https://doi.org/10.1007/s00603-017-1249-4
Dundurs J (1969) Discussion of edge-bonded dissimilar orthogonal elastic wedges under normal and shear loading. J Appl Mech 36:650–652
Elizalde C, Griffith WA, Miller T (2016) Thrust fault nucleation due to heterogeneous bedding plane slip: evidence from an Ohio coal mine. Eng Geol 206:1–17
Feng G, Wang P, Chugh YP (2018) Stability of gate roads next to an irregular yield pillar: a case study. Rock Mech Rock Eng. https://doi.org/10.1007/s00603-018-1533-y
Gao FQ, Stead D (2014) The application of a modified Voronoi logic to brittle fracture modelling at the laboratory and field scale. Int J Rock Mech Min Sci 68:1–14. https://doi.org/10.1016/j.ijrmms.2014.02.003
Gao F, Stead D, Coggan J (2014a) Evaluation of coal longwall caving characteristics using an innovative UDEC Trigon approach. Comput Geotech 55:448–460. https://doi.org/10.1016/j.compgeo.2013.09.020
Gao F, Stead D, Kang H (2014b) Simulation of roof shear failure in coal mine roadways using an innovative UDEC Trigon approach. Comput Geotech 61:33–41
Gong Q-M, Zhao J, Jiao Y-Y (2005) Numerical modeling of the effects of joint orientation on rock fragmentation by TBM cutters. Tunnell Undergr Space Technol 20:183–191
Gong Q, Jiao Y, Zhao J (2006) Numerical modelling of the effects of joint spacing on rock fragmentation by TBM cutters. Tunn Undergr Space Technol 21:46–55
Gudmundsson A (2011) Deflection of dykes into sills at discontinuities and magma-chamber formation. Tectonophysics 500:50–64. https://doi.org/10.1016/j.tecto.2009.10.015
Gui Y-L, Bui HH, Kodikara J, Zhang Q-B, Zhao J, Rabczuk T (2016) Modelling the dynamic failure of brittle rocks using a hybrid continuum-discrete element method with a mixed-mode cohesive fracture model. Int J Impact Eng 87:146–155
Gupta V, Yuan J, Martinez D (1993) Calculation, measurement, and control of interface strength in composites. J Am Ceram Soc 76:305–315
He M-Y, Hutchinson JW (1989) Crack deflection at an interface between dissimilar elastic materials. Int J Solids Struct 25:1053–1067. https://doi.org/10.1016/0020-7683(89)90021-8
Huang F, Zhu H, Xu Q, Cai Y, Zhuang X (2013) The effect of weak interlayer on the failure pattern of rock mass around tunnel—scaled model tests and numerical analysis. Tunn Undergr Space Technol 35:207–218. https://doi.org/10.1016/j.tust.2012.06.014
Itasca Consulting Group I (2011) Universal distinct element code (UDEC), version 5.0
Jongpradist P, Tunsakul J, Kongkitkul W, Fadsiri N, Arangelovski G, Youwai S (2015) High internal pressure induced fracture patterns in rock masses surrounding caverns: experimental study using physical model tests. Eng Geol 197:158–171
Ju J, Xu J (2013) Structural characteristics of key strata and strata behaviour of a fully mechanized longwall face with 7.0 m height chocks. Int J Rock Mech Min Sci 58:46–54. https://doi.org/10.1016/j.ijrmms.2012.09.006
Ju M, Li X, Yao Q, Liu S, Liang S, Wang X (2017) Effect of sand grain size on simulated mining-induced overburden failure in physical model tests. Eng Geol 226:93–106. https://doi.org/10.1016/j.enggeo.2017.05.015
Kang H, Lou J, Gao F, Yang J, Li J (2018) A physical and numerical investigation of sudden massive roof collapse during longwall coal retreat mining. Int J Coal Geol 188:25–36
Kazerani T, Zhao J (2010) Micromechanical parameters in bonded particle method for modelling of brittle material failure. Int J Numer Anal Methods Geomech 34:1877–1895. https://doi.org/10.1002/nag.884
Kazerani T, Yang Z-Y, Zhao J (2012) A discrete element model for predicting shear strength and degradation of rock joint by using compressive and tensile test data. Rock Mech Rock Eng 45:695–709
Kovar D, Thouless M, Halloran JW (1998) Crack deflection and propagation in layered silicon nitride/boron nitride ceramics. J Am Ceram Soc 81:1004–1112
Larsen B, Gudmundsson A, Grunnaleite I, Sælen G, Talbot MR, Buckley SJ (2010) Effects of sedimentary interfaces on fracture pattern, linkage, and cluster formation in peritidal carbonate rocks. Mar Pet Geol 27:1531–1550. https://doi.org/10.1016/j.marpetgeo.2010.03.011
Lee W, Clegg W (1996) The deflection of cracks at interfaces. In: Key engineering materials. Trans Tech Publ, pp 193–208
Li Y, Liu W, Yang C, Daemen JJK (2014) Experimental investigation of mechanical behavior of bedded rock salt containing inclined interlayer. Int J Rock Mech Min Sci 69:39–49. https://doi.org/10.1016/j.ijrmms.2014.03.006
Li J, Li H, Zhao J (2015a) An improved equivalent viscoelastic medium method for wave propagation across layered rock masses. Int J Rock Mech Min Sci 73:62–69
Li X, Ju M, Yao Q, Zhou J, Chong Z (2015b) Numerical investigation of the effect of the location of critical rock block fracture on crack evolution in a gob-side filling wall. Rock Mech Rock Eng 49:1041–1058. https://doi.org/10.1007/s00603-015-0783-1
Li S, Liu X, Li R, Su Y (2017) Shear deformation dominates in the soft adhesive layers of the laminated structure of flexible electronics. Int J Solids Struct 110:305–314
Ma J, Wang H, Weng L, Tan G (2004) Effect of porous interlayers on crack deflection in ceramic laminates. J Eur Ceram Soc 24:825–831
Miao X, Cui X, Wang J, Xu J (2011) The height of fractured water-conducting zone in undermined rock strata. Eng Geol 120:32–39. https://doi.org/10.1016/j.enggeo.2011.03.009
Palchik V (2002) Influence of physical characteristics of weak rock mass on height of caved zone over abandoned subsurface coal mines. Environ Geol 42:92–101. https://doi.org/10.1007/s00254-002-0542-y
Palchik V (2003) Formation of fractured zones in overburden due to longwall mining. Environ Geol 44:28–38. https://doi.org/10.1007/s00254-002-0732-7
Palchik V (2005) Localization of mining-induced horizontal fractures along rock layer interfaces in overburden: field measurements and prediction. Environ Geol 48:68–80. https://doi.org/10.1007/s00254-005-1261-y
Palchik V (2015) Bulking factors and extents of caved zones in weathered overburden of shallow abandoned underground workings. Int J Rock Mech Min Sci 79:227–240. https://doi.org/10.1016/j.ijrmms.2015.07.005
Peng SS (2008) Coal mine ground control
Pompidou S, Lamon J (2007) Analysis of crack deviation in ceramic matrix composites and multilayers based on the Cook and Gordon mechanism. Compos Sci Technol 67:2052–2060
Qian M, Shi P, Xu J (2003) Ground Pressure and Strata Control. China University of Mining and Technology Press, Xuzhou
Shen B, King A, Guo H (2008) Displacement, stress and seismicity in roadway roofs during mining-induced failure. Int J Rock Mech Min Sci 45:672–688
Shen W-l, Bai J-b, Li W-f, Wang X-y (2018) Prediction of relative displacement for entry roof with weak plane under the effect of mining abutment stress. Tunn Undergr Space Technol 71:309–317. https://doi.org/10.1016/j.tust.2017.08.023
Son M (2013) Adhesion strength at the shotcrete-rock contact in rock tunneling. Rock Mech Rock Eng 46:1237–1246
Sun S, Lin H, Ren L (2011) Applications of FLAC3D in geotechnical engineering. China Water&Power Press, Beijing
Wasantha P, Ranjith P, Zhao J, Shao S, Permata G (2015) Strain rate effect on the mechanical behaviour of sandstones with different grain sizes. Rock Mech Rock Eng 48:1883–1895
Xing H, Zhang Q, Ruan D, Dehkhoda S, Lu G, Zhao J (2018) Full-field measurement and fracture characterisations of rocks under dynamic loads using high-speed three-dimensional digital image correlation. Int J Impact Eng 113:61–72
Xu D-P, Feng X-T, Cui Y-J, Jiang Q (2015) Use of the equivalent continuum approach to model the behavior of a rock mass containing an interlayer shear weakness zone in an underground cavern excavation. Tunn Undergr Space Technol 47:35–51. https://doi.org/10.1016/j.tust.2014.12.006
Yan F, Feng X-T, Chen R, Xia K, Jin C (2012) Dynamic tensile failure of the rock interface between tuff and basalt. Rock Mech Rock Eng 45:341–348
Yao Q et al (2017) Numerical investigation of the effects of coal seam dip angle on coal wall stability. Int J Rock Mech Min Sci 100:298–309. https://doi.org/10.1016/j.ijrmms.2017.10.002
Yavuz H (2004) An estimation method for cover pressure re-establishment distance and pressure distribution in the goaf of longwall coal mines. Int J Rock Mech Min Sci 41:193–205. https://doi.org/10.1016/s1365-1609(03)00082-0
Zhang Q, Zhao J (2013) Determination of mechanical properties and full-field strain measurements of rock material under dynamic loads. Int J Rock Mech Min Sci 60:423–439
Zhang H, Elsworth D, Wan Z (2018) Failure response of composite rock-coal samples. Geomech Geophys Geo-Energy Geo-Resour 4:175–192
Zhao J (2000) Applicability of Mohr-Coulomb and Hoek-Brown strength criteria to the dynamic strength of brittle rock. Int J Rock Mech Min Sci 37:1115–1121
Zhao J-J, Zhang Y (2017) Studies on rock failure of layered rock in underground mining-face and control techniques. Geomech Geophys Geo-Energy Geo-Resour 3:405–414
Zheng Y, Chen C, Liu T, Song D, Meng F (2019) Stability analysis of anti-dip bedding rock slopes locally reinforced by rock bolts. Eng Geol 251:228–240
Zhou Y et al. (2011) Suggested methods for determining the dynamic strength parameters and mode-I fracture toughness of rock materials. In: The ISRM suggested methods for rock characterization, testing and monitoring: 2007–2014. Springer, pp 35–44
Acknowledgements
This work was supported by the China Scholarship Council-Monash University (CSC-Monash) Project (NO. 201606420068), the National Natural Science Foundation of China (NO. 41525009, NO. 41831281, NO. 51874283), and the National Key R&D Program of China (2018YFC0604703).
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Ju, M., Wang, D., Shi, J. et al. Physical and numerical investigations of bedding adhesion strength on stratified rock roof fracture with longwall coal mining. Geomech. Geophys. Geo-energ. Geo-resour. 7, 24 (2021). https://doi.org/10.1007/s40948-020-00209-2
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DOI: https://doi.org/10.1007/s40948-020-00209-2