Abstract
To investigate the distortion and damage properties of coal-rock combination (CRC) samples, the individual coal samples and rock samples and CRC were developed by similar materials with equal strength. Then, uniaxial compression (UC) tests and acoustic emission (AE) tests were performed on CRC samples with various rock-coal height ratios and loading rates. The strength, deformation, and AE properties of the CRC samples were analyzed to explore their failure mechanisms. The findings indicated that the individual coal samples and rock samples were mainly damaged by tensile splitting. For CRC samples, shear and tensile coupled failures were the main failure modes. Cracks are first generated from coal part and continue to expand to rock part. The coal-rock height ratio had little impact on the single AE event count peak value but had a certain influence on the cumulative number of AE event count. However, the loading rate had a large effect on the AE characteristics, and the strength and elastic modulus (E) of the CRC samples had linear or nonlinear increasing trend with increasing ratio of rock to coal height and loading rate. The research findings will have certain theoretical reference value for analyzing the mechanism of coal pillar failure.
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Abi E, Yuan H, Cong Y, Wang Z, Jiang M (2023) Experimental study on the entropy change failure precursors of marble under different stress paths. KSCE Journal of Civil Engineering 27(1):356–370, DOI: https://doi.org/10.1007/s12205-022-1975-3
Ali M, Wang E, Li Z, Wang X, Khan NM, Zang Z, Alarifi SS, Fissha Y (2023) Analytical damage model for predicting coal failure stresses by utilizing acoustic emission. Sustainability 15(2):1236, DOI: https://doi.org/10.3390/su15021236
Bai JW, Feng GR, Wang ZH, Wang SY, Qi TY, Wang PF (2019) Experimental investigations on the progressive failure characteristics of a sandwiched coal-rock system under uniaxial compression. Applied Sciences 9(6):1195, DOI: https://doi.org/10.3390/app9061195
Chakraborty S, Bisai R, Palaniappan SK, Pal SK (2019) Failure modes of rocks under uniaxial compression tests: An experimental approach. Journal of Advances in Geotechnical Engineering 2(3):1–8, DOI: https://doi.org/10.5281/zenodo.3461773
Chen SJ, Yin DW, Jiang N, Wang F, Guo WJ (2019) Simulation study on effects of loading rate on uniaxial compression failure of composite rock-coal layer. Geomechanics and Engineering 17(4):333–342, DOI: https://doi.org/10.12989/GAE.2019.17.4.333
Chen Y, Zuo JP, Song HQ, Feng LL, Shao GY (2018) Deformation and crack evolution of coal-rock combined body under cyclic loading-unloading effects. Journal of Mining & Safety Engineering 35(4):826–833, DOI: https://doi.org/10.13545/j.cnki.jmse.2018.04.022
Choi S, Jeong H, Cheon DS (2022) Prediction of mohr-coulomb constants of selected korean rocks based on extreme gradient boosting method and its evaluation. KSCE Journal of Civil Engineering 26(5):2468–2477, DOI: https://doi.org/10.1007/s12205-022-1388-3
Dambly MLT, Nejati M, Vogler D, Saar MO (2019) On the direct measurement of shear moduli in transversely isotropic rocks using the uniaxial compression test. International Journal of Rock Mechanics and Mining Sciences 113:220–240, DOI: https://doi.org/10.1016/j.ijrmms.2018.10.025
Das AJ, Paul PS, Mandal PK, Kumar R, Tewari S (2021) Investigation of failure mechanism of inclined coal pillars: Numerical modelling and tensorial statistical analysis with field validations. Rock Mechanics and Rock Engineering 54(6):3263–3289, DOI: https://doi.org/10.1007/s00603-021-02456-5
Fan Y, Chen J, Leng ZD, Yang GD, Liu XF, Tian B (2024a) Punching mechanism of air-deck stemming for drilling blasting and its influence on rock fragmentation. Rock Mechanics and Rock, DOI: https://doi.org/10.1007/s00603-024-03773-1
Fan Y, Yang GD, Cui XZ, Zhao XH, Wu JG, Wang LH (2024b) Low-frequency characteristics of vibrations induced by transient unloading of in situ stress and its influence on safety of a deeply buried tunnel. International Journal of Geomechanics, DOI: https://doi.org/10.1061/IJGNAI.GMENG-8190
Gao FQ, Kang HP, Yang L (2020) Experimental and numerical investigations on the failure processes and mechanisms of composite coal-rock specimens. Scientific Reports 10(1):13422, DOI: https://doi.org/10.1038/s41598-020-70411-5
Gong FQ, Ye H, Luo Y (2018) The effect of high loading rate on the behaviour and mechanical properties of coal-rock combined body. Shock and Vibration 2018:1–9, DOI: https://doi.org/10.1155/2018/4374530
Khazaei C, Hazzard J, Chalaturnyk R (2015) Damage quantification of intact rocks using acoustic emission energies recorded during uniaxial compression test and discrete element modeling. Computers and Geotechnics 67:94–102, DOI: https://doi.org/10.1016/j.compgeo.2015.02.012
Li XL, Chen SJ, Wang EY, Li ZH (2021) Corrigendum to “Rockburst mechanism in coal rock with structural surface and the microseismic (MS) and electromagnetic radiation (EMR) response” [Eng. Fail. Anal. 124 (2021) 105396]. Engineering Failure Analysis 128:105523, DOI: https://doi.org/10.1016/j.engfailanal.2021.105523
Li CJ, Xu Y, Ye ZY (2020) Energy dissipation and crushing characteristics of coal-rock-like combined body under impact loading. Chinese Journal of Geotechnical Engineering 42(5):981–988, DOI: https://doi.org/10.11779/CJGE202005022
Li FX, Yin DW, Wang F, Jiang N, Li XL (2022) Effects of combination mode on mechanical properties of bi-material samples consisting of rock and coal. Journal of Materials Research and Technology 19:2156–2170, DOI: https://doi.org/10.1016/j.jmrt.2022.05.174
Liu XS, Tan YL, Ning JG, Lu YW, Gu QH (2018) Mechanical properties and damage constitutive model of coal in coal-rock combined body. International Journal of Rock Mechanics and Mining Sciences 110:140–150, DOI: https://doi.org/10.1016/j.ijrmms.2018.07.020
Liu J, Wang EY, Song DZ, Yang SL, Niu Y (2014) Effects of rock strength on mechanical behavior and acoustic emission characteristics of samples composed of coal and rock. Journal of China Coal Society 39(4):685–691, DOI: https://doi.org/10.13225/j.cnki.jccs.2013.1490
Ma SZ, Liu KW, Guo TF, Yang JC, Li XD, Yan ZX (2022a) Experimental and numerical investigation on the mechanical characteristics and failure mechanism of cracked coal & rock-like combined sample under uniaxial compression. Theoretical and Applied Fracture Mechanics 122:103583, DOI: https://doi.org/10.1016/j.tafmec.2022.103583
Ma SZ, Lu KW, Guo TF, Huang XH, Zhou ZX (2022b) Numerical analysis of dynamic mechanical characteristics of brazilian splitting of coal-rock combination bodies. Chinese Journal of High Pressure Physics 36(5):128–140, DOI: https://doi.org/10.11858/gywlxb.20220589
Ma Q, Tan YL, Liu XS, Zhao ZH, Fan DY, Purev L (2021) Experimental and numerical simulation of loading rate effects on failure and strain energy characteristics of coal-rock composite samples. Journal of Central South University 28(10):3207–3222, DOI: https://doi.org/10.1007/s11771-021-4831-6
Okubo S, Fukui K, Qing XQ (2006) Uniaxial compression and tension tests of anthracite and loading rate dependence of peak strength. International Journal of Coal Geology 68(3–4):196–204, DOI: https://doi.org/10.1016/j.coal.2006.02.004
Shadrin A, Klishin V (2018) Acoustic emission of rock mass under the constant-rate fluid injection: IOP Conference Series. Earth and Environmental Science 134:012057, DOI: https://doi.org/10.1088/1755-1315/134/1/012057
Tan Y, Liu XS, Ning JG, Lu YW (2017) In situ investigations on failure evolution of overlying strata induced by mining multiple coal seams. Geotechnical Testing Journal 40(2):20160090, DOI: https://doi.org/10.1520/GTJ20160090
Tan YL, Liu XS, Shen B, Ning JG, Gu QH (2018) New approaches to testing and evaluating the impact capability of coal seam with hard roof and/or floor in coal mines. Geomechanics and Engineering 14(4):367–376, DOI: https://doi.org/10.12989/GAE.2018.14.4.367
Wang P, Jia HJ, Zheng PQ (2020a) Sensitivity analysis of bursting liability for different coal-rock combinations based on their inhomogeneous characteristics. Geomatics Natural Hazards and Risk 11:149–159, DOI: https://doi.org/10.1080/19475705.2020.1714754
Wang T, Ma Z (2022) Research on strain softening constitutive model of coal-rock combined body with damage threshold. International Journal of Damage Mechanics 31(1):22–42, DOI: https://doi.org/10.1177/10567895211019068
Wang T, Ma ZG, Gong P, Li N, Cheng SX (2020b) Analysis of failure characteristics and strength criterion of coal-rock combined body with different height ratios. Advances in Civil Engineering 2020:1–14, DOI: https://doi.org/10.1155/2020/8842206
Wang T, Qi FZ, Chang JC (2022a) Analysis of energy transmission and deformation characteristics of coal-rock combined bodies. Geofluids 2022:1–11, DOI: https://doi.org/10.1155/2022/5304250
Wang X, Tian LG (2018) Mechanical and crack evolution characteristics of coal-rock under different fracture-hole conditions: A numerical study based on particle flow code. Environmental Earth Sciences 77(8):297, DOI: https://doi.org/10.1007/s12665-018-7486-3
Wang TN, Zhai Y, Gao H, Li YB, Li Y, Sun WZ, Yan TY (2022b) A macroscopic elastic model of coal-rock combined body under static compression before cracking. Rock and Soil Mechanics 43(4):1031–1040, DOI: https://doi.org/10.16285/j.rsm.2021.1075
Xia ZG, Liu S, Bian Z, Song JH, Feng F, Jiang N (2021) Mechanical properties and damage characteristics of coal-rock combination with different dip angles. KSCE Journal of Civil Engineering 25(5): 1687–1699, DOI: https://doi.org/10.1007/s12205-021-1366-1
Xiong Y, Yang SL, Kong DZ, Song GF, Ma ZQ, Zuo YJ (2023) Analysis on early warning of coal sample failure based on crack development law and strain evolution characteristics. Engineering Failure Analysis 148:107170, DOI: https://doi.org/10.1016/j.engfailanal.2023.107170
Xu J, Ma L, Xiao XC, Wu D (2023) Experimental study of the formation process and behaviors of spalling in rock materials. Engineering Failure Analysis 143:106873, DOI: https://doi.org/10.1016/j.engfailanal.2022.106873
Yang Z, Li Y, Li X, Zhuang JY, Li H, Wang X, Wang YN, Du F (2021) Multifield coupling mechanism of unloading deformation and fracture of composite coal-rock. Shock and Vibration 2021:1–16, DOI: https://doi.org/10.1155/2021/2450330
Yang EH, Li SG, Lin HF, Zhao PX, Qin L, Zhao B (2022) Influence mechanism of coal thickness effect on strength and failure mode of coal-rock combination under uniaxial compression. Environmental Earth Sciences 81(17):429, DOI: https://doi.org/10.1007/s12665-022-10533-3
Yang K, Wei Z, Chi XL, Zhang YG, Dou LT, Liu WJ (2020) Experimental research on the mechanical characteristics and the failure mechanism of coal-rock composite under uniaxial load. Advances in Civil Engineering 2020:1–11, DOI: https://doi.org/10.1155/2020/8867809
Yin DW, Chen SJ, Ge Y, Liu R (2021) Mechanical properties of rock-coal bi-material samples with different lithologies under uniaxial loading. Journal of Materials Research and Technology 10:322–338, DOI: https://doi.org/10.1016/j.jmrt.2020.12.010
Yin DW, Chen SJ, Liu XQ, Ma HF (2018) Effect of joint angle in coal on failure mechanical behaviour of roof rock-coal combined body. Quarterly Journal of Engineering Geology and Hydrogeology 51(2):202–209, DOI: https://doi.org/10.1144/qjegh2017-041
Závacký M, Štefaňák J (2019) Strains of rock during uniaxial compression tests. Stavební obzor - Civil Engineering Journal 28(3), DOI: https://doi.org/10.14311/CEJ.2019.03.0032
Zhang H (2019) Study on the influence of local impact on coal-rock microstructures and equivalent theoretical model. MSc Thesis, China University of Mining Technology, Beijing, China (in Chinese)
Zhang CL, Dong Y, Feng RM, Peng NB, Zhang JH, Wu JK, Shen W, Du F (2021) Crack propagation law and failure characteristics of coal-rock combined body with the different inclination angle of prefabricated fissure. Geofluids 2021:1–13, DOI: https://doi.org/10.1155/2021/4348912
Zhang H, Lu CP, Liu B, Liu Y, Zhang N, Wang HY (2020) Numerical investigation on crack development and energy evolution of stressed coal-rock combination. International Journal of Rock Mechanics and Mining Sciences 133:104417, DOI: https://doi.org/10.1016/j.ijrmms.2020.104417
Zhao TB, Gu XB, Guo WY, Gong XF, Xiao YX, Kong B, Zhang CG (2021) Influence of rock strength on the mechanical behavior and P-velocity evolution of coal-rock combination specimen. Journal of Materials Research and Technology 12:1113–1124, DOI: https://doi.org/10.1016/j.jmrt.2021.03.059
Acknowledgments
This work was supported by the China Postdoctoral Science Foundation (No. 2023M732109), the Shandong Postdoctoral Science Foundation (No. SDCX-ZG-202303031), the Opening Foundation of Shandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation (No. CDPM2021FK02) and the Youth Innovation Team of Shandong Higher Education Institutions (No. 2022KJ214). We would like to acknowledge the editor and reviewers for their valuable comments, which have greatly improved this paper.
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Tian, M., Zhang, A., Yin, D. et al. Research on Mechanical Characteristics and Failure Mechanism of Coal-Rock Combined Bodies with Equal Strength. KSCE J Civ Eng (2024). https://doi.org/10.1007/s12205-024-2637-4
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DOI: https://doi.org/10.1007/s12205-024-2637-4