Energy evolution and structural health monitoring of coal under different failure modes: An experimental study

Abstract

Structural instability in underground engineering, especially in coal–rock structures, poses significant safety risks. Thus, the development of an accurate monitoring method for the health of coal–rock bodies is crucial. The focus of this work is on understanding energy evolution patterns in coal–rock bodies under complex conditions by using shear, splitting, and uniaxial compression tests. We examine the changes in energy parameters during various loading stages and the effects of various failure modes, resulting in an innovative energy dissipation-based health evaluation technique for coal. Key results show that coal bodies go through transitions between strain hardening and softening mechanisms during loading, indicated by fluctuations in elastic energy and dissipation energy density. For tensile failure, the energy profile of coal shows a pattern of “high dissipation and low accumulation” before peak stress. On the other hand, shear failure is described by “high accumulation and low dissipation” in energy trends. Different failure modes correlate with an accelerated increase in the dissipation energy before destabilization, and a significant positive correlation is present between the energy dissipation rate and the stress state of the coal samples. A novel mathematical and statistical approach is developed, establishing a dissipation energy anomaly index, W, which categorizes the structural health of coal into different danger levels. This method provides a quantitative standard for early warning systems and is adaptable for monitoring structural health in complex underground engineering environments, contributing to the development of structural health monitoring technology.

Keywords

energy dissipation / structural health monitoring / early warning / coal–rock mechanics / failure mode

References

[[1]] Xu P, Yang RS, Zuo JJ, et al.. Research progress of the fundamental theory and technology of rock blasting. Int. J. Miner. Metall. Mater., 2022, 29(4): 705,

[[2]] M. Wu, Y.C. Ye, Q.H. Wang, and N.Y. Hu, Development of rockburst research: A comprehensive review, Appl. Sci., 12(2022), No. 3, art. No. 974.

[[3]] S.Q. He, D.Z. Song, X.Q. He, et al., Coupled mechanism of compression and prying-induced rock burst in steeply inclined coal seams and principles for its prevention, Tunnelling Underground Space Technol., 98(2020), art. No. 103327.

[[4]] He XQ, Zhou C, Song DZ, et al.. Mechanism and monitoring and early warning technology for rockburst in coal mines. Int. J. Miner. Metall. Mater., 2021, 28(7): 1097,

[[5]] Ma YK, Nie BS, He XQ, Li XC, Meng JQ, Song DZ. Mechanism investigation on coal and gas outburst: An overview. Int. J. Miner. Metall. Mater., 2020, 27(7): 872,

[[6]] Xie HP, Li LY, Peng RD, Ju Y. Energy analysis and criteria for structural failure of rocks. J. Rock Mech. Geotech. Eng., 2009, 1(1): 11,

[[7]] Xie HP, Ju Y, Li LY, Peng RD. Energy mechanism of deformation and failure of rock masses. Chin. J. Rock Mech. Eng., 2008, 27(9): 1729

[[8]] Xie HP, Peng RD, Ju Y, Zhou HW. On energy analysis of rock failure. Chin. J. Rock Mech. Eng., 2005, 24(15): 2603

[[9]] Xie HP, Ju Y, Li LY. Criteria for strength and structural failure of rocks based on energy dissipation and energy release principles. Chin. J. Rock Mech. Eng., 2005, 24(17): 3003

[[10]] Xie HP, Peng RD, Ju Y. Energy dissipation of rock deformation and fracture. Chin. J. Rock Mech. Eng., 2004, 23(21): 3565

[[11]] Gong FQ, Yan JY, Luo S, Li XB. Investigation on the linear energy storage and dissipation laws of rock materials under uniaxial compression. Rock Mech. Rock Eng., 2019, 52(11): 4237,

[[12]] Gong FQ, Yan JY, Li XB, Luo S. A peak-strength strain energy storage index for rock burst proneness of rock materials. Int. J. Rock Mech. Min. Sci., 2019, 117: 76,

[[13]] Chen ZQ, He C, Ma GY, Xu GW, Ma CC. Energy damage evolution mechanism of rock and its application to brittleness evaluation. Rock Mech. Rock Eng., 2019, 52(4): 1265,

[[14]] Li DY, Sun Z, Xie T, Li XB, Ranjith PG. Energy evolution characteristics of hard rock during triaxial failure with different loading and unloading paths. Eng. Geol., 2017, 228: 270,

[[15]] Cui BQ, Feng GR, Bai JW, et al.. Failure characteristics and the damage evolution of a composite bearing structure in pillar-side cemented paste backfilling. Int. J. Miner. Metall. Mater., 2023, 30(8): 1524,

[[16]] Jiang YD, Li HT, Zhao YX, Zhou K. Effect of loading rate on energy accumulation and dissipation in rocks. J. China Univ. Min. Technol., 2014, 43(3): 369

[[17]] W.B. Shen, W.J. Yu, B. Pan, and K. Li, Rock mechanical failure characteristics and energy evolution analysis of coal–rock combination with different dip angles, Arabian. J. Geosci., 15(2022), No. 1, art. No. 93.

[[18]] Gao L, Gao F, Zhang ZZ, Xing Y. Research on the energy evolution characteristics and the failure intensity of rocks. Int. J. Min. Sci. Technol., 2020, 30(5): 705,

[[19]] Li P, Cai MF, Wang PT, Guo QF, Miao SJ, Ren FH. Mechanical properties and energy evolution of jointed rock specimens containing an opening under uniaxial loading. Int. J. Miner. Metall. Mater., 2021, 28(12): 1875,

[[20]] Chen GB, Zhang JW, He YL, Zhang GH, Li T. Derivation of pre-peak energy distribution formula and energy accumulation tests of coal–rock combined body. Rock Soil Mech., 2022, 43(Suppl. 2): 130

[[21]] Xiao XC, Fan YF, Wu D, Ding X, Wang L, Zhao BY. Energy dissipation feature and rock burst risk assessment in coal–rock combinations. Rock Soil Mech., 2019, 40(11): 4203

[[22]] Wang AW, Gao QS, Pan YS, Song YM, Li L. Bursting liability and energy dissipation laws of prefabricated borehole coal samples. J. China Coal Soc., 2021, 46(3): 959

[[23]] Yu H, Liu SW, Jia HS, Wang SL. Mechanical response and energy dissipation mechanism of closed single fractured sandstone under different confining pressures. J. Min. Saf. Eng., 2020, 37(2): 385

[[24]] Wang P, Xu JY, Fang XY, Wang PX. Energy dissipation and damage evolution analyses for the dynamic compression failure process of red-sandstone after freeze-thaw cycles. Eng. Geol., 2017, 221: 104,

[[25]] S. Yin, D.Z. Song, X.Q. He, et al., Structural health monitoring of building rock based on stress drop and acoustic-electric energy release, Struct. Control Health Monit., 29(2022), No. 2, art. No. e2875.

[[26]] Ning JG, Wang J, Jiang JQ, Hu SC, Jiang LS, Liu XS. Estimation of crack initiation and propagation thresholds of confined brittle coal specimens based on energy dissipation theory. Rock Mech. Rock Eng., 2018, 51(1): 119,

[[27]] Q.F. Ma, Z.H. Liu, Y.P. Qin, T.H. Jing, and S.L. Wang, Rock plastic-damage constitutive model based on energy dissipation, Rock Soil Mech., 42(2021), art. No. 1210.

[[28]] Gong FQ, Wang YL, Wang ZG, Pan JF, Luo S. A new criterion of coal burst proneness based on the residual elastic energy index. Int. J. Min. Sci. Technol., 2021, 31(4): 553,

[[29]] Gong FQ, Wang YL, Luo S. Rockburst proneness criteria for rock materials: Review and new insights. J. Cent. South Univ., 2020, 27(10): 2793,

[[30]] Zhang ZZ, Gao F. Experimental investigation on the energy evolution of dry and water-saturated red sandstones. Int. J. Min. Sci. Technol., 2015, 25(3): 383,

[[31]] Song DZ, Wang EY, Liu J. Relationship between EMR and dissipated energy of coal rock mass during cyclic loading process. Saf. Sci., 2012, 50(4): 751,

[[32]] Solecki R, Conant RJ. . Advanced Mechanics of Materials, 2003 London Oxford University Press

[[33]] Wei MH, Song DZ, He XQ, Lou Q, Qiu LM, Li ZL. Characteristics of electromagnetic vector field generated from rock fracturing. J. Rock Mech. Geotech. Eng., 2023, 15(2): 457,

[[34]] S. Yin, D.Z. Song, X.Q. He, et al., Time-frequency evolution law and generation mechanism of electromagnetic radiation in coal friction process, Eng. Geol., 294(2021), art. No. 106377.

[[35]] H.L. Wang, D.Z. Song, Z.L. Li, X.Q. He, S.R. Lan, and H.F. Guo, Acoustic emission characteristics of coal failure using automatic speech recognition methodology analysis, Int. J. Rock Mech. Min. Sci., 136(2020), art. No. 104472.

[[36]] Song DZ, He XQ, Wang EY, Li ZL, Liu J. . Rockburst Evolutionary Process and Energy Dissipation Characteristics, 2020 Singapore Springer,

[[37]] Lacidogna G, Accornero F, Carpinteri A. Influence of snap-back instabilities on Acoustic Emission damage monitoring. Eng. Fract. Mech., 2019, 210: 3,