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Mechanical properties and permeability evolution of gas-bearing coal under phased variable speed loading and unloading

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Abstract

It is of great significance for the analysis and prediction of coal-gas outburst disasters to understand the mechanical properties and permeability evolution of coal and rock under conditions of stope stress evolution. In this study, mechanical tests were conducted on gas-bearing coal under four stress paths, including conventional triaxial compression (CTC), phased variable speed triaxial compression (PVSTC), unloading confining pressure (UCP), and phased variable speed unloading confining pressure (PVSUCP), simultaneously measuring the permeability in mechanical tests. The mechanical properties and permeability evolutions in gas-bearing coal under four different stress paths were compared. The obtained results show that the deviatoric stress-strain curves of gas-bearing coal under four stress paths could be divided into five stages: compaction, linear elasticity, plastic deformation, stress drop, and residual stress stage. The permeability-strain curves under four stress paths could also be divided into five stages: fast drop, slow decrease, slow increase, sharp increase, and slowed growth. Compared to the CTC conditions, the peak strain and strength of coal under PVSTC conditions increased. Furthermore, the stress drop and energy release under PVSTC were more intense at the moment of instability failure. Compared to both loading paths, the coal was damaged more rapidly under unloading paths and the damage was stronger. Additionally, among both unloading paths, the time required for the failure of coal under PVSUCP was shorter than that under UCP, while the damage under PVSUCP was stronger. The strength characteristics of the gas-bearing coal under PVSTC and PVSUCP still met the Mohr–Coulomb criterion. This preliminary study has guiding significance for the understanding of the co-occurrence mechanisms of coal-gas outburst disasters.

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Abbreviations

CTC:

Conventional triaxial compression

PVSTC:

Phased variable speed triaxial compression

UCP:

Unloading confining pressure

PVSUCP:

Phased variable speed unloading confining pressure

References

  • Al-Ajmi AM, Zimmerman RW (2005) Relation between the Mogi and the Coulomb failure criteria. Int J Rock Mech Min Sci 42:431–439

    Article  Google Scholar 

  • An FH, Cheng YP, Wang L, Li W (2013) A numerical model for outburst including the effect of adsorbed gas on coal deformation and mechanical properties. Comput Geotech 54:222–231

    Article  Google Scholar 

  • Aziz NI, Ming-Li W (1999) The effect of sorbed gas on the strength of coal-an experimental study. Geotech Geol Eng 17:387–402

    Article  Google Scholar 

  • Beamish BB, Crosdale PJ (1998) Instantaneous outbursts in underground coal mines: an overview and association with coal type. Int J Coal Geol 35:27–55

    Article  Google Scholar 

  • Chen HD, Cheng YP, Zhou HX, Li W (2013) Damage and permeability development in coal during unloading. Rock Mech Rock Eng 46:1377–1390

    Article  Google Scholar 

  • Chen H, Cheng Y, Ren T, Zhou H, Liu Q (2014) Permeability distribution characteristics of protected coal seams during unloading of the coal body. Int J Rock Mech Min Sci 71:105–116

    Article  Google Scholar 

  • Clarkson CR, Bustin RM (1999) The effect of pore structure and gas pressure upon the transport properties of coal: a laboratory and modeling study. 1. Isotherms and pore volume distributions. Fuel 78:1333–1344

    Article  Google Scholar 

  • Du F, Wang K, Wang G, Jiang YF, Xin CP, Zhang X (2018) Investigation on acoustic emission characteristics during deformation and failure of gas-bearing coal-rock combined bodies. J Loss Prevent Proc 55:253–266

    Article  Google Scholar 

  • Fairhurst CE, Hudson JA (1999) Draft ISRM suggested method for the complete stress-strain curve for intact rock in uniaxial compression. Int J Rock Mech Min Sci 36:281–289

    Google Scholar 

  • Gentzis T, Deisman N, Chalaturnyk RJ (2007) Geomechanical properties and permeability of coal from the foothills and mountain regions of western Canada. Int J Coal Geol 69:153–164

    Article  Google Scholar 

  • George JDS, Barakat MA (2001) The change in effective stress associated with shrinkage from gas desorption in coal. Int J Coal Geol 45:105–113

    Article  Google Scholar 

  • Goodman AL, Favors RN, Larsen JW (2006) Argonne coal structure rearrangement caused by sorption of CO2. Energy Fuel 20:2537–2543

    Article  Google Scholar 

  • Harpalani S, Chen G (1995) Estimation of changes in fracture porosity of coal with gas emission. Fuel 74:1491–1498

    Article  Google Scholar 

  • Hoek E, Brown ET (1982) Empirical strength criterion for rock masses. J Geotech Eng-Div 106:1013–1035

    Google Scholar 

  • Hoek E, Wood D, Shah S (1992) Modified Hoek-Brown failure criterion for jointed rock masses. Proceedings of the international ISRM symposium on rock characterization. Chester, UK

    Google Scholar 

  • Jaeger JC, Cook NGW (1979) Fundamentals of rock mechanics, third ed. John Wiley & Sons

  • Kasani HA, Chalaturnyk RJ (2017) Influence of high pressure and temperature on the mechanical behavior and permeability of a fractured coal. Energies 10(7):854. https://doi.org/10.3390/en10070854

    Article  Google Scholar 

  • Kumar H, Elsworth D, Liu J, Pone D, Mathews JP (2012) Optimizing enhanced coalbed methane recovery for unhindered production and CO2, injectivity. Int J Greenh Gas Con 11(6):86–97

    Article  Google Scholar 

  • Kumar H, Elsworth D, Liu J, Pone D, Mathews JP (2015) Permeability evolution of propped artificial fractures in coal on injection of CO2. J Pet Sci Eng 133:695–704

    Article  Google Scholar 

  • Kumar H, Elsworth D, Mathews JP, Marone C (2016) Permeability evolution in sorbing media: analogies between organic-rich shale and coal. Geofluids 16:43–55

    Article  Google Scholar 

  • Labuz JF, Zang A (2012) Mohr-Coulomb failure criterion. Rock Mech Rock Eng 45:975–979

    Article  Google Scholar 

  • Lajtai EZ, Duncan EJS, Carter BJ (1991) The effect of strain rate on rock strength. Rock Mech Rock Eng 24:99–109

    Article  Google Scholar 

  • Li Z, Wang E, Ou J, Liu Z (2015) Hazard evaluation of coal and gas outbursts in a coal-mine roadway based on logistic regression model. Int J Rock Mech Min Sci 80:185–195

    Article  Google Scholar 

  • Liu KD (2017) Mechanical properties of ram coal containing gas under high triaxial stress compression. Chin J Rock Mech Eng 36:380–393

    Google Scholar 

  • Lu CP, Dou LM, Liu H, Liu HS, Liu B, Du BB (2012) Case study on microseismic effect of coal and gas outburst process. Int J Rock Mech Min Sci 53:101–110

    Article  Google Scholar 

  • Masoudian MS, Airey DW, El-Zein A (2014) Experimental investigations on the effect of CO2 on mechanics of coal. Int J Coal Geol 12-23:s128–s129

    Google Scholar 

  • Palmer I, Mansoori J (1996) How permeability depends on stress and pore pressure in coalbeds: a new model. SPE Reser Eval En 1:539–544

    Google Scholar 

  • Siriwardane H, Haljasmaa I, Mclendon R, Irdi G, Soong Y, Bromhal G (2009) Influence of carbon dioxide on coal permeability determined by pressure transient methods. Int J Coal Geol 77:109–118

    Article  Google Scholar 

  • Somerton WH, Söylemezoḡlu IM, Dudle RC (1975) Effect of stress on permeability of coal. Int J Rock Mech Min Sci 12:129–145

    Article  Google Scholar 

  • Viete DR, Ranjith PG (2007) The mechanical behaviour of coal with respect to CO 2 sequestration in deep coal seams. Fuel 86:2667–2671

    Article  Google Scholar 

  • Wang S, Elsworth D, Liu J (2011) Permeability evolution in fractured coal: the roles of fracture geometry and water-content. Int J Coal Geol 87:13–25

    Article  Google Scholar 

  • Wang K, Du F, Wang G (2017a) Investigation of gas pressure and temperature effects on the permeability and steady-state time of chinese anthracite coal: an experimental study. J Nat Gas Sci Eng 40:179–188

    Article  Google Scholar 

  • Wang K, Du F, Wang G (2017b) The influence of methane and CO2 adsorption on the functional groups of coal: insights from a Fourier transform infrared investigation. J Nat Gas Sci Eng 45:358–367

    Article  Google Scholar 

  • Wang K, Du F, Zhang X, Wang L, Xin C (2017c) Mechanical properties and permeability evolution in gas-bearing coal–rock combination body under triaxial conditions. Environ Earth Sci 76:815 1–19

    Article  Google Scholar 

  • Wold MB, Connell LD, Choi SK (2008) The role of spatial variability in coal seam parameters on gas outburst behaviour during coal mining. Int J Coal Geol 75:1–14

    Article  Google Scholar 

  • Xie G, Yin Z, Wang L, Hu Z, Zhu C (2017) Effects of gas pressure on the failure characteristics of coal. Rock Mech Rock Eng 50:1–13

    Article  Google Scholar 

  • Xue D, Zhou H, Wang Z, Ren W (2010) Failure mechanism and mining-induced mechanical properties of coal under different loading rates. J China Coal Soc 41:595–602

    Google Scholar 

  • Xue Y, Ranjith PG, Gao F, Zhang D, Cheng H, Chong Z, Hou P, Xue Y, Ranjith PG, Gao F (2017) Mechanical behaviour and permeability evolution of gas-containing coal from unloading confining pressure tests. J Nat Gas Sci Eng 40:336–346

    Article  Google Scholar 

  • Yuan L (2016) Control of coal and gas outbursts in Huainan mines in China: a review. J Rock Mech Geotech Eng 8:559–567

    Article  Google Scholar 

  • Yin G, Jiang C, Wang JG, Xu J (2015) Geomechanical and flow properties of coal from loading axial stress and unloading confining pressure tests. Int J Rock Mech Min Sci 76:155–161

    Article  Google Scholar 

  • Zhang Q, Fan X, Liang Y, Li M, Li G, Ma T, Nie W (2017) Mechanical behavior and permeability evolution of reconstituted coal samples under various unloading confining pressures-implications for wellbore stability analysis. Energies 10(3):292. https://doi.org/10.3390/en10030292

    Article  Google Scholar 

  • Zhou X, Qian Q, Yang H (2010) Effect of loading rate on fracture characteristics of rock. J Cent South Univ Techno 17:150–155

    Article  Google Scholar 

Download references

Acknowledgments

This research is financially supported by the State Key Research Development Program of China (2016YFC0801402, 2016YFC0600708), National Natural Science Foundation of China (51474219, 51604153, 51874314), the Open Funds of Hebei State Key Laboratory of Mine Disaster Prevention (KJZH2017K02), the Joint Fund Project of Guizhou Science and Technology Department and Bijie Science and Technology Bureau and Institute of Circular Economy (LH[2017]7520), the Guizhou Science and Technology Support Program ([2017]2820), and the Yue Qi Distinguished Scholar Project, China University of Mining & Technology, Beijing. Feng Du would like to acknowledge the Fund of China Scholarship Council (CSC) for his study in Department of Civil Engineering and Engineering Mechanics, Columbia University.

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Authors and Affiliations

  1. Beijing Key Laboratory for Precise Mining of Intergrown Energy and Resources, China University of Mining and Technology (Beijing), Beijing, 100083, China

    Chengpeng Xin, Kai Wang, Feng Du & Xiang Zhang

  2. School of Resource & Safety Engineering, China University of Mining & Technology (Beijing), Beijing, 100083, China

    Chengpeng Xin, Kai Wang, Feng Du & Xiang Zhang

  3. School of Mining Engineering, Guizhou University of Engineering Science, Bijie, 551700, China

    Chengpeng Xin & Yilei Liu

  4. Hebei State Key Laboratory of Mine Disaster Prevention, North China Institute of Science and Technology, Beijing, 101601, China

    Kai Wang

  5. Mine Safety Technology Branch, China Coal Research Institute, Beijing, 100013, China

    Gongda Wang

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  1. Chengpeng Xin
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  2. Kai Wang
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  3. Feng Du
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  4. Xiang Zhang
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Correspondence to Kai Wang.

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Xin, C., Wang, K., Du, F. et al. Mechanical properties and permeability evolution of gas-bearing coal under phased variable speed loading and unloading. Arab J Geosci 11, 747 (2018). https://doi.org/10.1007/s12517-018-4117-y

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