Abstract
Mining disturbances may cause fissure water in the sandstones of a coal seam roof to link up with the coal seam, further causing changes in the moisture conditions of coal–rock systems such as immediate roofs, coal seams, and immediate floors. The varying moisture content influences the mechanical properties and failure precursor symptoms of coal–rock systems. In this study, we carried out uniaxial compressive experiments on coal–rock combinations under dry, natural moisture, and saturated conditions and measured the acoustic emission (AE) and infrared radiation (IR) data. The results show that the combinations can be classified according to the varying water absorption capacities of coal, mudstone, and siltstone with intrusion time. We classified them into a rapid water absorption stage (0 to 2 h), a slow water absorption stage (> 2 to 14 h), and a stable stage (> 14 h). At the same stage, the water absorption capacities can be ranked as coal > mudstone > siltstone. From dry to saturated, the uniaxial compressive strengths, modulus of elasticity, and peak strain of the coal–rock combination specimens is reduced by 37.5, 8.9, and 35.2% respectively. Cracks produced by coal–rock combinations were concentrated mainly on the surface of the coal portions. Before and after the peak failure, the IR temperature of the dry coal–rock combination increases first and then decreases, while the IR temperature of the natural moisture and saturated coal–rock combinations decreases first, then increases, then decreases again. From dry to saturated, the time interval and stress-level interval between the AE precursor point and IR precursor point of the specimens increases by 1.68 times and 4.5 times, respectively. These outcomes provide a useful reference for studying monitoring and early warning of coal and rock interactions and coal and rock pillar instability under the effect of water–rock interaction in engineering practice.
Similar content being viewed by others
References
Chen GQ, Li TB, Guo F, Wang YK (2017a) Brittle mechanical characteristics of hard rock exposed to moisture. B Eng Geol Environ 76:219–230
Chen T, Yao QL, Wei F, Chong ZH, Zhou J, Wang CB, Li J (2017b) Effects of water intrusion and loading rate on mechanical properties of and crack propagation in coal–rock combinations. J Cent South Univ 24:423–431
Dou LM, Mu ZL, Li ZL, Cao AY, Gong SY (2014) Research progress of monitoring, forecasting, and prevention of rockburst in underground coal mining in China. Int J Coal Sci Tech 1(3):278–288
Fang J, Yao QL, Wang WN, Tang CJ, Wang G (2018) Experimental study on damage characteristics of siltstone under water action. J Chin Coal Soc 43(Suppl 2):412–419 (In Chinese)
Guo J, Feng GR, Qi TY, Wang PF, Yang J, Li Z, Bai J, du X, Wang Z (2018) Dynamic mechanical behavior of dry and water saturated igneous rock with AE monitoring. Shock Vib 2018:1–14
Huang BX, Liu JW (2013) The effect of loading rate on the behavior of specimens composed of coal and rock. Int J Rock Mech Min 61:23–30
Huang JW, Liu SJ, Ni Q, Mao WF, Gao X (2018) Experimental study of extracting weak infrared signals of rock induced by cyclic loading under the strong interference background. Appl Sci–Basel:8
Hudson JA, Harrison JP (2000) Engineering Rock Mechanics–An Introduction to the Principles. Appl Mech Rev 55(2):72
Jaeger JC, Cook NGW, Zimmerman RW (2007) Fundamentals of rock mechanics. Blackwell, London
Lashkaripour GR (2002) Predicting mechanical properties of mudrock from index parameters. B Eng Geol Environ 61:73–77
Li HM, Li HG, Gao BB, Jiang DJ, Feng JF (2015) Study of AE and mechanical characteristics of coal specimens under different loading rates. Shock Vib
Li N, Zhang SC, Zou YS, Ma XF, Zhang ZP, Li SH, Chen M, Sun Y (2018) Acoustic emission response of laboratory hydraulic fracturing in layered shale. Rock Mech Rock Eng 51:3395–3406
Liu B, Yang RS, Guo DM, Zhang DZ (2004) Burst–prone experiments of coal–rock combination at −1100 m level in Suncun coal mine. Chin J Rock Mech Eng 14:2402–2408 (In Chinese)
Liu GT, Hu Y, Li PH (2006) Behavior of soaking rock and its effects on design of arch dam. Chin J Rock Mech Eng 25(9):1729–1734 (In Chinese)
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. J Chin Coal Soc 39(4):685–691 (in Chinese)
Liu XX, Liang ZZ, Zhang YB, Liang P, Tian BZ (2018) Experimental study on the monitoring of rockburst in tunnels under dry and saturated conditions using AE and infrared monitoring. Tunn Undergr Sp Tech 82:517–528
Lockner DA (1993) The role of acoustic emission in the study of rock fracture. Int J Rock Mech Min 30(7):883–899
Lou Q, He XQ (2018) Experimental study on IR temperature field of concrete under uniaxial compression. Infrared Phys Techn 90:20–30
Lu CP, Liu GJ, Wang HY, Xue JH (2015) Numerical investigation of rockburst effect of shock wave on underground roadway. Shock Vib 2015:1–10
Lyu Q, Ranjith PG, Long XP, Ji B (2016) Experimental investigation of mechanical properties of black shales after CO2–water–rock interaction. Materials 9
Ma LQ, Sun H (2018) Spatial–temporal IR precursors of coal failure under uniaxial compressive loading. Infrared Phys Techn 93:144–153
Ma LQ, Sun H, Zhang Y, Zhou T, Li K, Guo JS (2016) Characteristics of IR of coal specimens under uniaxial loading. Rock Mech Rock Eng 49:1567–1572
Ma LQ, Sun H, Zhang Y, Hu HL, Zhang CG (2018a) The role of stress in controlling IR during coal and rock failures. Strain 54
Ma CQ, Wang P, Jiang LS, Wang CS (2018b) Deformation and control countermeasure of surrounding rocks for water-dripping roadway below a contiguous seam goaf. Processes 6
Meng QB, Zhang MW, Han LJ, Pu H, Chen YL (2018) AE characteristics of red sandstone specimens under uniaxial cyclic loading and unloading compression. Rock Mech Rock Eng 51:969–988
Pappalardo G, Mineo S, Zampelli SP, Cubito A, Calcaterra D (2016) Infrared thermography proposed for the estimation of the cooling rate index in the remote survey of rock masses. Int J Rock Mech Min 83:182–196
Petukhov IM, Linkov AM (1979) The theory of post-failure deformations and the problem of stability in rock mechanics. Int J Rock Mech Min 16(2):57–76
Rathnaweera TD, Ranjith PG, Perera MSA, Haque A, Lashin A, Al Arifi N et al (2015) CO2-induced mechanical behaviour of Hawkesbury sandstone in the Gosford basin: an experimental study. Mat Sci Eng A-Struct 641:123–137
Roy DG, Singh TN, Kodikara J, Das R (2017) Effect of water saturation on the fracture and mechanical properties of sedimentary rocks. Rock Mech Rock Eng 50:2585–2600
Sun XM, Xu HC, He MC, Zhang F (2017) Experimental investigation of the occurrence of rockburst in a rock specimen through infrared thermography and AE. Int J Rock Mech Min 93:250–259
Tan YL, Guo WY, Gu QH, Zhao TB, Yu FH, Hu SC, Yin YC (2016) Research on the rockburst tendency and AE characteristics of inhomogeneous coal–rock combination bodies. Shock Vib 2016:1–11
Tang SB, Yu CY, Heap MJ, Chen PZ, Ren YG (2018) The Influence of water saturation on the short- and long-term mechanical behavior of red sandstone. Rock Mech Rock Eng 51:2669–2687
Vakili A, Hebblewhite BK (2010) A new cavability assessment criterion for Longwall Top Coal Caving. Int J Rock Mech Min 47(8):1317–1329
Vishal V, Ranjith PG, Singh TN (2015) An experimental investigation on behaviour of coal under fluid saturation, using AE. J Nat Gas Sci Eng 22:428–436
Wang G, Zhang YZ, Jiang YJ, Liu PX, Guo YS, Liu JK, Ma M, Wang K, Wang S (2018) Shear behaviour and AE characteristics of bolted rock joints with different roughnesses. Rock Mech Rock Eng 51:1885–1906
Wang P, Jia HJ, Zheng PQ (2020) Sensitivity analysis of bursting liability for different coal–rock combinations based on their inhomogeneous characteristics. Geomat Nat Haz Risk 11(1):149–159
Wu LX, Cui CY, Geng NG, Wang JH (2000) Remote sensing rock mechanics (RSRM) and associated experimental studies. Int J Rock Mech Min. 37:879–888
Wu LX, Liu SJ, Wu YH, Wang CY (2006) Precursors for rock fracturing and failure—Part II: IRR T-curve abnormalities. Int J Rock Mech Min 43:483–493
Yang RS, Li YL, Guo DM, Yao L, Yang TM, Li TT (2017) Failure mechanism and control technology of water-immersed roadway in high-stress and soft rock in a deep mine. Int J Rock Mech Min 27:245–252
Yao QL, Zhang FT, Ding XL, Zhang L, Jiang GA (2009) Experimental research on instability mechanism of silty mudstone roofs under action of water and its application. Proced Earth Plan Sc 1:402–408
Yao QL, Li XH, Zhou J, Ju MH, Chong ZH, Zhao B (2015) Experimental study of strength characteristics of coal specimens after water intrusion. Arab J Geosci 8:6779–6789
Yao QL, Chen T, Ju MH, Liang S, Liu YP, Li XH (2016) Effects of water intrusion on mechanical properties of and crack propagation in coal. Rock Mech Rock Eng 49:4699–4709
Zhang YB, Chen BB, Jing GH (2013) The research of water effect on infrared radiation of concrete failure process. Appl Mech Mater 256–259:2754–2759
Zhao YX, Jiang YD (2010) Acoustic emission and thermal infrared precursors associated with bump-prone coal failure. Int J Coal Geol 83(1):11–20
Zhao YX, Jiang YD, Han ZR (2007) Experimental study on acoustic and thermal infrared characteristics of bump-prone coal. Chin J Rock Mech Eng 5:965–971 (In Chinese)
Zhao ZH, Wang WM, Wang LH, Dai CQ (2015) Compression–shear strength criterion of coal–rock combination model considering interface effect. Tunn Undergr Sp Tech 47:193–199
Zhao YC, Yang TH, Xu T, Zhang PH, Shi WH (2018) Mechanical and energy release characteristics of different water-bearing sandstones under uniaxial compression. Int J Damage Mech 27:640–656
Zingg S, Anagnostou G (2018) Tunnel face stability and the effectiveness of advance drainage measures in water-bearing ground of non-uniform permeability. Rock Mech Rock Eng 51:187–202
Zuo JP, Pei JL, Liu JF, Peng RD, Li YC (2011) 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, Wang ZF, Zhou HW, Pei JL, Liu JF (2013) Failure behavior of a rock–coal–rock combined body with a weak coal interlayer. Int J Min Sci Tech 6:907–912
Funding
This work was supported by the “Fundamental Research Funds for the Central Universities” (2017XKZD06).
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest to this work.
Additional information
Responsible Editor: Zeynal Abiddin Erguler
Rights and permissions
About this article
Cite this article
Yao, Q., Wang, W., Zhu, L. et al. Effects of moisture conditions on mechanical properties and AE and IR characteristics in coal–rock combinations. Arab J Geosci 13, 615 (2020). https://doi.org/10.1007/s12517-020-05610-5
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s12517-020-05610-5