Abstract
To obtain a comprehensive understanding of the difference between deep and shallow rocks, and the damage evolution laws of a rock mass at different depths, a case study was conducted on the Pingdingshan Coal Mine. Mechanical behavior and real-time acoustic emission (AE) testing were carried out to investigate the spatiotemporal evolution of the damage in coal at different depths under triaxial compression conditions. Coal samples from different depths (300, 600, 700, 850, and 1050 m) of the same coal seam were collected, and the geostresses measured at each depth were considered in the two-factor simulation method. The AE characteristics and the spatiotemporal evolution of the coal damage at different depths were also obtained. The testing results show that under the influence of the confining pressure caused by increased geostress, the AE activity and the average scale of the cracks in the coal decreased with increasing depth. The deeper coal developed more small cracks and more plastic strain. With increasing depth, the fractal dimension reduction mode of the spatial distribution of AE under continuous loading changed from dropping suddenly from a higher dimension level (2.97) at a higher stress level (70%) to dropping slowly from a lower dimension level (2.63) at a lower stress level (20%). The generation of AE events was more uniform in the time dimension, while the spatial distribution became more uneven and clustered. With continuous loading, the number of AE events and damage in the shallow coal increased, and the dimension of the spatial distribution of AE decreased sharply during the failure stage before the peak stress was reached. With increasing depth, the damage initiation of coal shifted to an earlier time, while the damage evolution process was more stable and orderly, and ended with a higher damage degree. The sudden damage increase of deep coal was not obvious when approaching to failure. The shallow coal was more brittle and prone to sudden failure with the centralized release of AE energy after reaching the peak stress. However, the deeper coal exhibited a more plastic behavior and the plastic deformation became more obvious during the loading process with the gradual development of damage. These research results deepen the understanding of rock mechanics at different depths, promote the study of the difference in the damage laws of deep and shallow rock masses, and provide a meaningful reference for microseismic monitoring and disaster prevention in deep rock engineering.
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Abbreviations
- A, Ac :
-
Cumulative AE energy and total cumulative AE energy (J)
- C, Cc :
-
Cumulative AE parameters and total cumulative AE parameters
- C w :
-
The number of cumulative AE characteristics for a unit area of the coal specimen
- D0, Dc :
-
The initial damage variable and critical damage variable
- D s :
-
Dimension of the spatial distribution of AE
- D :
-
Damage variable
- F, Fc :
-
Cumulative AE counts and total cumulative AE counts
- M(r), C1 :
-
AE event number and height–diameter ratio of a sample in the column covering method
- N, Nc :
-
Cumulative AE events and total cumulative AE events
- ri, hi :
-
Radius and height of the cylinder in the column covering method (m)
- Sd, S :
-
The cross-sectional area of damage and the cross-sectional area of the undamaged material at the initial stage (m2)
- D mc :
-
CT microcrack diameter (mm)
- χ :
-
Crack density with a diameter greater than Dmc (mm−3)
- ε 1 :
-
Axial strain
- μ :
-
Poisson’s ratio
- σ v :
-
Vertical stress (MPa)
- σ H :
-
Maximum horizontal stress (MPa)
- σ h :
-
Minimum horizontal stress (MPa)
- σ 1 :
-
Axial stress (MPa)
- σ 3 :
-
Confining pressure (MPa)
- σ R :
-
Axial residual strength (MPa)
- σ ci :
-
Crack initiation stress (MPa)
- σ cd :
-
Crack unstable growing stress (MPa)
- σ c :
-
Peak stress (MPa)
References
Ai T, Zhang R, Liu J, Ren L (2012) Space-time evolution rules of acoustic emission location of unloaded coal sample at different loading rates. Int J Min Sci Technol 22(6):847–854
Bruning T, Karakus M, Nguyen GD, Goodchild D (2018) Experimental study on the damage evolution of brittle rock under triaxial confinement with full circumferential strain control. Rock Mech Rock Eng 51(11):3321–3341
Chang S, Lee C (2004) Estimation of cracking and damage mechanisms in rock under triaxial compression by moment tensor analysis of acoustic emission. Int J Rock Mech Min Sci 41:1069–1086
Chen BR, Feng XT, Li QP, Luo RZ, Li S (2015) Rock burst intensity classification based on the radiated energy with damage intensity at Jinping II Hydropower Station, China. Rock Mech Rock Eng 48:289–303
Chen ZQ, He C, Ma GY, Xu GW, Ma CC (2019) Energy damage evolution mechanism of rock and its application to brittleness evaluation. Rock Mech Rock Eng 52(4):1265–1274
Cox S, Meredith P (1993) Microcrack formation and material softening in rock measured by monitoring acoustic emissions. Int J Rock Mech Min Sci 30:11–24
Dai F, Li B, Xu NW, Meng GT, Wu JY, Fan YL (2016) Microseismic monitoring of the left bank slope at the Baihetan Hydropower Station, China. Rock Mech Rock Eng 50:225–232
Gao MZ, Zhang R, Xie J, Peng GY, Yu B, Ranjith PG (2018) Field experiments on fracture evolution and correlations between connectivity and abutment pressure under top coal caving conditions. Int J Rock Mech Min Sci 111:84–93
Hatzor Y, Palchik V (1997) The influence of grain size and porosity on crack initiation stress and critical flaw length in dolomites. Int J Rock Mech Min Sci 34(5):805–816
He MC, Xie HP, Peng SP, Jiang YD (2005) Study on rock mechanics in deep mining engineering. Chin J Rock Mechan Eng 24(16):2803–2813
Hoek E, Martin CD (2014) Fracture initiation and propagation in intact rock-a review. J Rock Mech Geotech Eng 6(4):287–300
Jiang HK, Zhang L, Zhou YS (2000) Granite deformation and behavior of acoustic emission sequence under the temperature and pressure condition in different crust depths. Acta Seismol Sin 22(4):395–403
Kachanov LM (1958) Time of the rupture process under creep conditions. Izv Akad Nauk S S R Otd Tech Nauk 8:26–31
Katsuyama K (1996) Application of AE techniques. FENG Xia-ting, translator. Metallurgy Industry Press, Beijing
Kim JS, Lee KS, Cho WJ, Choi HJ, Cho GC (2015) A comparative evaluation of stress–strain and acoustic emission methods for quantitative damage assessments of brittle rock. Rock Mech Rock Eng 48(2):495–508
Kong B, Wang EY, Li ZH, Wang XR, Chen L, Kong XG (2016) Nonlinear characteristics of acoustic emissions during the deformation and fracture of sandstone subjected to thermal treatment. Int J Rock Mech Min 90:43–52
Li JP, Zhou CB (2004) Experimental research on acoustic emission characteristics of rock mass. Rock Soil Mech 25(3):374–378
Li SJ, Feng XT, Li ZH, Chen BR, Jiang Q, Wu SY, Hu B, Xu JS (2011) In situ experiments on width and evolution characteristics of excavation damaged zone in deeply buried tunnels. Sci China Technol Sci 54(S1):167–174
Li JC, Li HB, Ma GW, Zhao J (2012a) A time-domain recursive method to analyze transient wave propagation across rock joints. Geophys J Int 188(2):631–644
Li SJ, Feng XT, Li ZH, Chen BR, Zhang CR, Zhou H (2012b) In situ monitoring of rockburst nucleation and evolution in the deeply buried tunnels of Jinping II hydropower station. Eng Geol 137–138:85–96
Li JC, Li HB, Ma GW, Zhou YX (2013) Assessment of underground tunnel stability to adjacent tunnel explosion. Tunn Undergr Space Technol 35(35):227–234
Li XL, Wang EY, Li ZH, Song DZ, Qiu LM (2016) Rock burst monitoring by integrated microseismic and electromagnetic radiation methods. Rock Mech Rock Eng 49(11):4393–4406
Li HB, Liu MC, Xing WB, Shao S, Zhou JW (2017) Failure mechanisms and evolution assessment of the excavation damaged zones in a large-scale and deeply buried underground powerhouse. Rock Mech Rock Eng 50(7):1883–1900
Liu JP, Xu SD, Li YH, Lei G (2019) Analysis of rock mass stability based on mining-induced seismicity: a case study at the Hongtoushan Copper Mine in China. Rock Mech Rock Eng 52(1):265–276
Lockner D (1993) The role of acoustic emission in the study of rock fracture. Int J Rock Mech Min Sci Geomech Abstr 30(7):883–899
Munson DE (1997) Constitutive model of creep in rock salt applied to underground room closure. Int J Rock Mech Min Sci 34(2):233–247
Peng K, Liu ZP, Zou QL, Zhang ZY, Zhou JQ (2019) Static and dynamic mechanical properties of granite from various burial depths. Rock Mech Rock Eng 52(10):3545–3566
Perras MA, Wannenmacher H, Diederichs MS (2014) Underground excavation behaviour of the Queenston formation: tunnel back analysis for application to shaft damage dimension prediction. Rock Mech Rock Eng 48(4):1647–1671
Sellers EJ, Klerck P (2000) Modelling of the effect of discontinuities on the extent of the fracture zone surrounding deep tunnels. Tunn Undergr Space Technol 15(4):463–469
Singh J, Ramamurthy T, Rao GV (1989) Strength of rocks at depth. Int Soc Rock Mech 27(2):37–44
Thomas B, Murat K, Giang DN, David G (2018) Experimental study on the damage evolution of brittle rock under triaxial confinement with full circumferential strain control. Rock Mech Rock Eng 51(11):3321–3341
Wang SH, Lee CL, Ranjith PG, Tang CA (2009) Modeling the effects of heterogeneity and anisotropy on the excavation damaged/disturbed zone (EDZ). Rock Mech Rock Eng 42(2):229–258
Xiao YX, Feng XT, Hudson JA, Chen BR, Feng GL, Liu JP (2016) ISRM suggested method for in situ microseismic monitoring of the fracturing process in rock masses. Rock Mech Rock Eng 49(1):343–369
Xie HP (1996) Fractals in rock mechanics. Science Press, Beijing
Xie HP (2017) Research framework and anticipated results of deep rock mechanics and mining theory. Adv Eng Sci 49(2):1–16
Xie HP, Gao F, Ju Y, Gao MZ, Zhang R, Gao YN, Liu JF, Xie LZ (2015) Quantitative definition and investigation of deep mining. J China Coal Soc 40(1):1–10
Xie J, Gao MZ, Zhang R, Li SW, Tan Q, Qiu ZQ (2016) Lessons learnt from measurements of vertical pressure at a top coal mining face at datong tashan mines, china. Rock Mech Rock Eng 49(7):2977–2983
Xie H, Gao M, Zhang R, Peng G, Wang W, Li A (2019) Study on the mechanical properties and mechanical response of coal mining at 1000 m or deeper. Rock Mech Rock Eng 52(5):1475–1490
Yan P, Lu WB, Chen M, Hu YG, Zhou CB, Wu XX (2014) Contributions of in-situ stress transient redistribution to blasting excavation damage zone of deep tunnels. Rock Mech Rock Eng 48(2):715–726
Yang SQ, Ni HM, Wen S (2014) Spatial acoustic emission evolution of red sandstone during multi-stage triaxial deformation. J Cent South Univ 21(8):3316–3326
Zhang JG (2013) Review and prospect of comprehensive gas prevention and control of China Pingmei Shenma Group. Min Saf Environ Prot 40(5):82–86
Zhang HQ, He YN, Tang CA, Ahmad Bashir, Han LJ (2009) Application of an improved flow-stress-damage model to the criticality assessment of water inrush in a mine: a case study. Rock Mech Rock Eng 42(6):911–930
Zhang R, Dai F, Gao MZ, Xu NW, Zhang CP (2015a) Fractal analysis of acoustic emission during uniaxial and triaxial loading of rock. Int J Rock Mech Min Sci 79:241–249
Zhang ZP, Zhang R, Xie HP, Liu JF, Were P (2015b) 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 ZT, Zhang R, Xie HP, Gao MZ, Xie J (2016) Mining-induced coal permeability change under different mining layouts. Rock Mech Rock Eng 49(9):3753–3768
Zhang R, Ai T, Gao MZ, Zhang GQ, Zhou C (2017) Basic theory and experimental study of rock acoustic emission. Sichuan University Press, Chengdu
Zhang ZP, Xie HP, Zhang R, Zhang ZT, Mingzhong Gao, Jia ZQ, Xie J (2018a) Deformation damage and energy evolution characteristics of coal at different depths. Rock Mech Rock Eng 52(5):1491–1503
Zhang J, Ai C, Li YW, Che MG, Gao R, Zeng J (2018b) Energy-based brittleness index and acoustic emission characteristics of anisotropic coal under triaxial stress condition. Rock Mech Rock Eng 51(11):3343–3360
Zhang R, Ai T, Ren L, Li G (2019) Failure characterization of three typical coal-bearing formation rocks using acoustic emission monitoring and x-ray computed tomography techniques. Rock Mech Rock Eng 52(6):1945–1958
Zhao XG, Cai M, Wang J, Ma LK (2013) Damage and acoustic emission characteristics of the Beishan granite. Int J Rock Mech Min Sci 64:258–269
Zhou HW, Xie HP, Zuo JP, Du SH (2010) Experimental study of the effect of depth on mechanical parameters of rock. Chin Sci Bull 55(34):3276–3284
Zhou HW, Wang ZH, Wang CS, Liu JF (2019) On acoustic emission and post-peak energy evolution in Beishan granite under cyclic loading. Rock Mech Rock Eng 52(1):283–288
Zong Y, Han L, Wei J, Wen S (2016) Mechanical and damage evolution properties of sandstone under triaxial compression. Int J Min Sci Technol 26(4):601–607
Acknowledgements
The authors are grateful for the financial support from the National Natural Science Foundation of China (Nos. 51622402, 51804203, and 51804204), the Science and Technology Planning Project of Sichuan Province, China (No. 2017TD0007), the Fundamental Research Funds for the Central Universities (No. 2012017yjsy170).
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Jia, Z., Xie, H., Zhang, R. et al. Acoustic Emission Characteristics and Damage Evolution of Coal at Different Depths Under Triaxial Compression. Rock Mech Rock Eng 53, 2063–2076 (2020). https://doi.org/10.1007/s00603-019-02042-w
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DOI: https://doi.org/10.1007/s00603-019-02042-w