Abstract
The deformation and failure behaviour of coal–rock combined body under uniaxial compression were investigated experimentally and numerically. The mechanical parameters, including the uniaxial compressive strength (UCS), elastic modulus and full-scale stress–strain curves, were obtained. A detailed analysis of the evolution of the internal cracks based on X-ray computed tomography (CT) observations and acoustic emission (AE) locations is presented. The experimental results show that the mechanical properties and deformation failure characteristics of the coal–rock combined body were governed mainly by the coal. The UCS and elastic modulus of the coal–rock combined body were slightly larger than those of the coal and most of the cracks occurring in the coal were a result of the uniaxial compression. Furthermore, a numerical simulation was conducted to validate the experimental evidence. Finally, based on this understanding, a constitutive relationship was proposed using the natural strain described in Hooke’s law for accurate modelling of the deformation of the coal–rock body. A good agreement was obtained between the numerical results and experimental data during the pre-peak regime.
Similar content being viewed by others
References
Brown ET, Bray JW, Santarelli FJ (1989) Influence of stress-dependent elastic moduli on stresses and strains around axisymmetric boreholes. Rock Mech Rock Eng 22(3):189–203
Buehler MJ, Abraham FF, Gao HJ (2003) Hyperelasticity governs dynamic fracture at a critical length scale. Nature 426(6963):141–146
Cao A, Dou L, Cai W, Gong S, Liu S, Jing G (2015) Case study of seismic hazard assessment in underground coal mining using passive tomography. Int J Rock Mech Min Sci 78:1–9
Freed AD (1995) Natural strain. J Eng Mater Technol 117(4):379–385
Freund LB (1990) Dynamic fracture mechanics. Cambridge University Press, Cambridge
Gao FQ, Stead D, Kang HP (2014) Numerical investigation of the scale effect and anisotropy in the strength and deformability of coal. Int J Coal Geol 136:25–37
Gao F, Stead D, Kang H (2015) Numerical simulation of squeezing failure in a coal mine roadway due to mining-induced stresses. Rock Mech Rock Eng 48(4):1635–1645
Ghasemi E, Ataei M, Shahriar K (2014) An intelligent approach to predict pillar sizing in designing room and pillar coal mines. Int J Rock Mech Min Sci 65:86–95
Jaeger JC, Cook NGW, Zimmerman RW (2007) Fundamentals of rock mechanics, 4th edn. Blackwell, Oxford
Kang HP, Lou JF, Gao FQ, Yang JH, Li JZ (2018) A physical and numerical investigation of sudden massive roof collapse during longwall coal retreat mining. Int J Coal Geol 188:25–36
Konicek P, Soucek K, Stas L, Singh R (2013) Long-hole destress blasting for rockburst control during deep underground coal mining. Int J Rock Mech Min Sci 61:141–153
Kwinta A (2012) Prediction of strain in a shaft caused by underground mining. Int J Rock Mech Min Sci 55:28–32
Li YP, Yang CH, Daemen JJK, Yin XY, Chen F (2009) A new Cosserat-like constitutive model for bedded salt rocks. Int J Numer Anal Meth Geomech 33(15):1691–1720
Li LC, Yang TH, Liang ZZ, Zhu WC, Tang CN (2011) Numerical investigation of groundwater outbursts near faults in underground coal mines. Int J Coal Geol 85(3–4):276–288
Li YP, Liu W, Yang CH, Daemen JJK (2014) Experimental investigation of mechanical behavior of bedded rock salt containing inclined interlayer. Int J Rock Mech Min Sci 69:39–49
Lionço A, Assis A (2000) Behaviour of deep shafts in rock considering nonlinear elastic models. Tunn Undergr Sp Tech 15(4):445–451
Liu HH, Rutqvist J, Berryman JG (2009) On the relationship between stress and elastic strain for porous and fractured rock. Int J Rock Mech Min Sci 46(2):289–296
Liu HH, Rutqvist J, Birkholzer JT (2011) Constitutive relationships for elastic deformation of clay rock: data analysis. Rock Mech Rock Eng 44(4):463–468
Liu J, Wang EY, Song DZ, Wang SH, Niu Y (2015) Effect of rock strength on failure mode and mechanical behavior of composite samples. Arab J Geosci 8(7):4527–4539
Meng Z, Shi X, Li G (2016) Deformation, failure and permeability of coal-bearing strata during longwall mining. Eng Geol 208:69–80
Nawrocki PA, Dusseault MB, Bratli RK, Xu G (1998) Assessment of some semi-analytical models for non-linear modelling of borehole stresses. Int J Rock Mech Min Sci 35(4–5):522
Paterson MS, Wong TF (2005) Experimental rock deformation—the brittle field, 2nd edn. Springer, New York
Petukhov IM, Linkov AM (1979) The theory of post-failure deformations and the problem of stability in rock mechanics. Int J Rock Mech Min Sci Geomech Abstr 16:57–76
Qian QH (2004) The current development of nonlinear rock mechanics: the mechanics problems of deep rock mass. In: Chinese Society of Rock Mechanics and Engineering (ed) Proceedings of the 8th rock mechanics and engineering conference. Science Press, Beijing, pp 10–17 (in Chinese)
Singh M, Samadhiya NK, Kumar A, Kumar V, Singh B (2015) A nonlinear criterion for triaxial strength of inherently anisotropic rocks. Rock Mech Rock Eng 48(4):1387–1405
Tsang CF, Bernier F, Davies C (2005) Geohydromechanical processes in the excavation damaged zone in crystalline rock, rock salt, and indurated and plastic clays—in the context of radioactive waste disposal. Int J Rock Mech Min Sci 42:109–125
Ulusay R, Hudson JA (2007) The complete ISRM suggested methods for rock characterization, testing and monitoring: 1974–2006. Commission on Testing Methods, International Society of Rock Mechanics
Wang H, Jiang Y, Zhao Y, Zhu J, Liu S (2013) Numerical investigation of the dynamic mechanical state of a coal pillar during longwall mining panel extraction. Rock Mech Rock Eng 46(5):1211–1221
Wang T, Jiang YD, Zhan SJ, Wang C (2014) Frictional sliding tests on combined coal–rock samples. J Rock Mech Geotech Eng 6(3):280–286
Wang G, Wu M, Wang R, Xu H, Song X (2017a) Height of the mining-induced fractured zone above a coal face. Eng Geol 216:140–152
Wang K, Du F, Zhang X, Wang L, Xin C (2017b) Mechanical properties and permeability evolution in gas-bearing coal–rock combination body under triaxial conditions. Environ Earth Sci 76(24):815
Wood DS (1973) Patterns and magnitudes of natural strain in rocks. Phil Trans R Soc Lond A 274(1239):373–382
Xie HP, Zhao XP, Liu JF, Zhang R, Xue DJ (2012a) Influence of different mining layouts on the mechanical properties of coal. Int J Min Sci Technol 22:749–755
Xie HP, Zhou HW, Xue DJ, Wang HW, Zhang R, Gao F (2012b) Research and consideration on deep coal mining and critical mining depth. J China Coal Soc 37(4):535–542 (in Chinese)
Yang W, Lin BQ, Zhai C, Li XZ, An S (2012) How in situ stresses and the driving cycle footage affect the gas outburst risk of driving coal mine roadway. Tunn Undergr Sp Technol 31:139–148
Yang W, Wang H, Lin BQ, Wang YK, Mao XB, Zhang JG, Lyu YC, Wang M (2018) Outburst mechanism of tunnelling through coal seams and the safety strategy by using “strong–weak” coupling circle-layers. Tunn Undergr Sp Technol 74:107–118
Zhang Z, Zhang R, Xie H, Liu J, Were P (2015) Differences in the acoustic emission characteristics of rock salt compared with granite and marble during the damage evolution process. Environ Earth Sci 73(11):6987–6999
Zhang Y, Chen Y, Yu R, Hu L, Irfan M (2017) Effect of loading rate on the felicity effect of three rock types. Rock Mech Rock Eng 50(6):1673–1681
Zhao ZH, Wang WM, Wang LH, Dai CQ (2015) Compression–shear strength criterion of coal–rock combination model considering interface effect. Tunn Undergr Sp Technol 47:193–199
Zhu SY, Jiang ZQ, Zhou KJ, Peng GQ, Yang CW (2014) The characteristics of deformation and failure of coal seam floor due to mining in Xinmi coal field in China. B Eng Geol Environ 73(4):1151–1163
Zuo JP, Li HT, Xie HP, Ju Y, Peng SP (2008) A nonlinear strength criterion for rock-like materials based on fracture mechanics. Int J Rock Mech Min Sci 45(4):594–599
Zuo JP, Peng SP, Li YJ, Chen ZH, Xie HP (2009) Investigation of karst collapse based on 3-D seismic technique and DDA method at Xieqiao coal mine, China. Int J Coal Geol 78(4):276–287
Zuo JP, Pei JL, Liu JF, Peng R, Li YC (2011a) Investigation on acoustic emission behavior and its time–space evolution mechanism in failure process of coal–rock combined body. Chin J Rock Mech Eng 30(8):1564–1570 (in Chinese)
Zuo JP, Xie HP, Wu AM, Liu J (2011b) Investigation on failure mechanisms and mechanical behaviors of deep coal–rock single body and combined body. Chin J Rock Mech Eng 30(1):84–92 (in Chinese)
Zuo JP, Xie HP, Dai F, Ju Y (2014) Three-point bending test investigation of the fracture behavior of siltstone after thermal treatment. Int J Rock Mech Min Sci 70:133–143
Zuo JP, Liu HH, Li HT (2015) A theoretical derivation of the Hoek–Brown failure criterion for rock materials. J Rock Mech Geotech Eng 7(4):361–366
Zuo JP, Chen Y, Zhang JW, Wang JT, Sun YJ, Jiang GH (2016) Failure behavior and strength characteristics of coal–rock combined body under different confining pressures. J China Coal Soc 41:2706–2713 (in Chinese)
Acknowledgements
The authors gratefully acknowledge the support from the National Natural Science Foundation of China (51622404 and 11572343), Yueqi Distinguished Scholar of CUMTB, the State Key Research Development Program of China (2016YFC0801404), National Program for Support of Top-notch Young Professionals and China Postdoctoral Science Foundation (2017 M620048 and 2018 T110103).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Chen, Y., Zuo, J., Liu, D. et al. Deformation failure characteristics of coal–rock combined body under uniaxial compression: experimental and numerical investigations. Bull Eng Geol Environ 78, 3449–3464 (2019). https://doi.org/10.1007/s10064-018-1336-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10064-018-1336-0