Skip to main content
SpringerLink
Log in

Mechanical characteristics and crack evolution in specimens with double over-excavated cavities: experimental and numerical investigations

  • Published:
Computational Particle Mechanics Aims and scope Submit manuscript

Abstract

The mechanically over-excavated cavity along the borehole represents an innovative technology designed to enhance permeability in soft coal seams. This study aims to elucidate the complex mechanisms that influence the mechanical properties and crack evolution of over-excavated cavities. Uniaxial compression tests were performed on coal specimens with double over-excavated cavities, and the impact of cavity length–height ratio and shape on mechanical properties and crack evolution was investigated using digital image correlation techniques and acoustic emission (AE) measurements. Discrete element method simulations provided deeper insights into stress evolution and crack behavior around the cavities. The presence of an over-excavated cavity significantly affected the specimen’s mechanical properties, with the effect’s magnitude closely linked to the length–height ratio. As this ratio decreased, the peak stress and elastic modulus of the specimen increased. Specimens containing elliptical cavities demonstrated higher elastic modulus and peak stress compared to those with rectangular cavities of the same length. Crack initiation and propagation displayed distinct features, such as a sudden surge in AE counts and the appearance of strain concentration regions. The failure mode of the specimen was dominated by shear failure combined with tensile failure, and spalling of the specimen appeared as the length–height ratio decreased, indicating stronger damage. Numerical simulations aligned well with experimental findings, revealing tensile and shear cracks as predominant, with failure resulting from crack coalescence. Specimens containing rectangular cavities were more prone to failure than those with elliptical cavities due to stress concentration in corners. The maximum compressive principal stress was concentrated at the tips of the left and right flaws. The release and transfer of stress concentration zones played a pivotal role in influencing the evolution and behavior of cracks, ultimately impacting the overall mechanical response and failure characteristics of the specimen. The research findings provide valuable insights for optimizing the parameters of mechanically over-excavated cavities in coal mines, enhancing performance and safety.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19

Similar content being viewed by others

References

  1. Xia T, Zhou F, Liu J, Hu S, Liu Y (2014) A fully coupled coal deformation and compositional flow model for the control of the pre-mining coal seam gas extraction. Int J Rock Mech Min 72:138–148

    Article  Google Scholar 

  2. Zhou F, Xia T, Wang X, Zhang Y, Sun Y, Liu J (2016) Recent developments in coal mine methane extraction and utilization in China: a review. J Nat Gas Sci Eng 31:437–458

    Article  Google Scholar 

  3. Zhang R, Cheng Y, Yuan L, Zhou H, Wang L, Zhao W (2019) Enhancement of gas drainage efficiency in a special thick coal seam through hydraulic flushing. Int J Rock Mech Min 124:104085

    Article  Google Scholar 

  4. Zou Q-L, Lin B-Q, Liu T, Zhou Y, Zhang Z, Yan F-Z (2014) Variation of methane adsorption property of coal after the treatment of hydraulic slotting and methane pre-drainage: a case study. J Nat Gas Sci Eng 20:396–406

    Article  Google Scholar 

  5. Liu M, Kong L-A, Hao F-C, Xin X, Wei G, Liu Y (2005) Application of hydraulic flushing technology in severe outburst coal. J China Coal Soc 30(4):451–454

    Google Scholar 

  6. Liu Y, Ren P, Xia S, Sun Y (2009) Analysis of pressure-relief and permeability improvement effect of hydraulic flushing. J Henan Polytech Univ 28(6):695–699

    Google Scholar 

  7. Chang Z, Xi B, Zhao Y, Zhao L (2008) Mechanics of breaking coal by water jet. J China Coal Soc 33(9):983–987

    Google Scholar 

  8. Linghu J, An F, Wang L (2022) Permeability improvement mechanism and application of large-diameter mechanical caving drilling technology for promoting coal gas drainage. Arab J Geosci 15(10):792

    Article  Google Scholar 

  9. Hao C, Cheng Y, Liu H, Wang L, Liu Q (2019) A novel technology for high-efficiency borehole-enlarging to enhance gas drainage in coal seam by mechanical cutting assisted by waterjet. Energy Source Part A Recover Utiliz Environ Effects 44(1):1336–1353

    Google Scholar 

  10. Zhongyi M, Chun L, Mingyao W, Yonglong W (2023) Mechanical behaviour and fracture evolution of coal specimens containing an over-excavated hole: experimental study and numerical modelling. Strain 59(5):e12443

    Article  Google Scholar 

  11. Zhou XP, Zhang JZ, Yang SQ, Berto F (2021) Compression-induced crack initiation and growth in flawed rocks: a review. Fatigue Fract Eng Mater Struct 44(7):1681–1707

    Article  Google Scholar 

  12. Xiong F, Liu X, Zhou X, Lin G, Liu D, Han Y, Xu B, He C, Wang Z (2022) Mechanical behaviours of sandstone containing intersecting fissures under uniaxial compression. J Rock Mech Geotechn Eng 14(2):460–476

    Article  Google Scholar 

  13. Yang S-Q, Jing H-W (2011) Strength failure and crack coalescence behavior of brittle sandstone samples containing a single fissure under uniaxial compression. Int J Fract 168(2):227–250

    Article  Google Scholar 

  14. Wong LNY, Li H-Q (2013) Numerical study on coalescence of two pre-existing coplanar flaws in rock. Int J Solids Struct 50(22):3685–3706

    Article  Google Scholar 

  15. Cao P, Liu T, Pu C, Lin H (2015) Crack propagation and coalescence of brittle rock-like specimens with pre-existing cracks in compression. Eng Geol 187:113–121

    Article  Google Scholar 

  16. Wong LNY, Einstein HH (2009) Crack coalescence in molded gypsum and Carrara marble: Part 1 macroscopic observations and interpretation. Rock Mech Rock Eng 42(3):475–511

    Article  Google Scholar 

  17. Yang S-Q, Huang Y-H, Jing H-W, Liu X-R (2014) Discrete element modeling on fracture coalescence behavior of red sandstone containing two unparallel fissures under uniaxial compression. Eng Geol 178:28–48

    Article  Google Scholar 

  18. Zhao Z, Zhou D (2016) Mechanical properties and failure modes of rock samples with grout-infilled flaws: a particle mechanics modeling. J Nat Gas Sci Eng 34:702–715

    Article  Google Scholar 

  19. Haeri H, Shahriar K, Marji MF, Moarefvand P (2014) Cracks coalescence mechanism and cracks propagation paths in rock-like specimens containing pre-existing random cracks under compression. J Central South Univ 21(6):2404–2414

    Article  Google Scholar 

  20. Zhang JZ, Zhou XP, Zhou LS, Berto F (2019) Progressive failure of brittle rocks with non-isometric flaws: insights from acousto-optic-mechanical (AOM) data. Fatigue Fract Eng Mater Struct 42(8):1787–1802

    Article  Google Scholar 

  21. Miao S, Pan P-Z, Wu Z, Li S, Zhao S (2018) Fracture analysis of sandstone with a single filled flaw under uniaxial compression. Eng Fract Mech 204:319–343

    Article  Google Scholar 

  22. Zhu QQ, Li DY, Han ZY, Li XB, Zhou ZL (2019) Mechanical properties and fracture evolution of sandstone specimens containing different inclusions under uniaxial compression. Int J Rock Mech Min 115:33–47

    Article  Google Scholar 

  23. Wu H, Zhao G, Liang W (2020) Mechanical properties and fracture characteristics of pre-holed rocks subjected to uniaxial loading: a comparative analysis of five hole shapes. Theor Appl Fract Mech 105:102433

    Article  Google Scholar 

  24. Tan L, Zhou Z, Cai X, Rui Y (2022) Analysis of mechanical behaviour and fracture interaction of multi-hole rock mass with DIC measurement. Measurement 191:110794

    Article  Google Scholar 

  25. Liu T, Lin B, Yang W (2017) Mechanical behavior and failure mechanism of pre-cracked specimen under uniaxial compression. Tectonophysics 712–713:330–343

    Article  Google Scholar 

  26. Liu X-R, Yang S-Q, Huang Y-H, Cheng J-L (2019) Experimental study on the strength and fracture mechanism of sandstone containing elliptical holes and fissures under uniaxial compression. Eng Fract Mech 205:205–217

    Article  Google Scholar 

  27. Fan X, Li K, Lai H, Xie Y, Cao R, Zheng J (2018) Internal stress distribution and cracking around flaws and openings of rock block under uniaxial compression: a particle mechanics approach. Comput Geotech 102:28–38

    Article  Google Scholar 

  28. Yao D, Jiang N, Wang X, Jia X, Lv K (2022) Mechanical behaviour and failure characteristics of rocks with composite defects of different angle fissures around hole. Bull Eng Geol Environ 81(7):290

    Article  Google Scholar 

  29. Bai-quan L, Ting L, Quan-le Z, Chuan-jie Z, Fa-zhi Y, Zhen Z (2014) Crack propagation patterns and energy evolution rules of coal within slotting disturbed zone under various lateral pressure coefficients. Arab J Geosci 8(9):6643–6654

    Article  Google Scholar 

  30. Cheng L, Xu J, Peng S, Liu Y, Chen G, Li X, Qin Y (2018) Mesoscopic crack initiation, propagation, and coalescence mechanisms of coal under shear loading. Rock Mech Rock Eng 52(6):1979–1992

    Article  Google Scholar 

  31. Zhang H, Lu C-P, Liu B, Liu Y, Zhang N, Wang H-Y (2020) Numerical investigation on crack development and energy evolution of stressed coal-rock combination. Int J Rock Mech Min 133:104417

    Article  Google Scholar 

  32. Zhang L, Ren T, Li X, Tan L (2021) Acoustic emission, damage and cracking evolution of intact coal under compressive loads: experimental and discrete element modelling. Eng Fract Mech 252:107690

    Article  Google Scholar 

  33. Hao D, Tu S, Zhang C, Tu H (2020) Quantitative characterization and three-dimensional reconstruction of bituminous coal fracture development under rock mechanics testing. Fuel 267:107690

    Article  Google Scholar 

  34. He Z, Gong F, Wu W, Wang W (2021) Experimental investigation of the mechanical behaviors and energy evolution characteristics of red sandstone specimens with holes under uniaxial compression. Bull Eng Geol Env 80(7):5845–5865

    Article  Google Scholar 

  35. Zeng W, Yang S-Q, Tian W-L (2018) Experimental and numerical investigation of brittle sandstone specimens containing different shapes of holes under uniaxial compression. Eng Fract Mech 200:430–450

    Article  Google Scholar 

  36. Zhou Z, Tan L, Cao W, Zhou Z, Cai X (2017) Fracture evolution and failure behaviour of marble specimens containing rectangular cavities under uniaxial loading. Eng Fract Mech 184:183–201

    Article  Google Scholar 

  37. Potyondy DO (2012) A flat-jointed bonded-particle material for hard rock. In: 46th U.S. rock mechanics/geomechanics symposium

  38. Itasca (2019) PFC 6.0 Documentation, user’s guide, itasca consulting group, Inc., Minneapolis, MN, USA

  39. Zhang X-P, Wong LNY (2012) Crack initiation, propagation and coalescence in rock-like material containing two flaws: a numerical study based on bonded-particle model approach. Rock Mech Rock Eng 46(5):1001–1021

    Article  Google Scholar 

  40. Zhang X-P, Wong LNY (2013) Displacement field analysis for cracking processes in bonded-particle model. Bull Eng Geol Env 73(1):13–21

    Article  Google Scholar 

  41. Chen M, Yang S-Q, Ranjith PG, Zhang Y-C (2020) Cracking behavior of rock containing non-persistent joints with various joints inclinations. Theoret Appl Fract Mech 109:102701

    Article  Google Scholar 

  42. Zhao Y, Chen C, Qi Q, Wu S (2022) Rotation and deflection of 3D principal stress axes induced by a prefabricated single flaw in sandstone: a numerical investigation based on DEM. Theor Appl Fract Mech 120:103430

    Article  Google Scholar 

  43. Zhao Y, Li B, Wu S, Chen L (2022) Failure mechanism of brittle rock with 3D parallel preset flaws based on the particle displacement trend method. Theor Appl Fract Mech 117:103193

    Article  Google Scholar 

  44. Zhang X-P, Zhang Q, Wu S (2017) Acoustic emission characteristics of the rock-like material containing a single flaw under different compressive loading rates. Comput Geotech 83:83–97

    Article  Google Scholar 

  45. Chang X, Zhang X, Dang F, Zhang B, Chang F (2022) Failure behavior of sandstone specimens containing a single flaw under true triaxial compression. Rock Mech Rock Eng 55(4):2111–2127

    Article  Google Scholar 

  46. Zhang K, Jiang Z, Liu X, Zhang K, Zhu H (2022) Quantitative characterization of the fracture behavior of sandstone with inclusions: experimental and numerical investigation. Theor Appl Fract Mech 121:103429

    Article  Google Scholar 

  47. Gong F, He Z, Jiang Q (2022) Internal mechanism of reducing rockburst proneness of rock under high stress by real-time drilling pressure relief. Rock Mech Rock Eng 55(8):5063–5081

    Article  Google Scholar 

Download references

Acknowledgements

This research was supported by the National Natural Science Funds of China (52074283) and the Research Fund of State and Local Joint Engineering Laboratory for Gas Drainage and Ground Control of Deep Mines (Henan Polytechnic University) (SJF202001).

Author information

Authors and Affiliations

  1. Key Laboratory of Gas and Fire Control for Coal Mines, China University of Mining and Technology (CUMT), Xuzhou, 221116, Jiangsu, People’s Republic of China

    Man Zhongyi

  2. School of Safety Engineering, China University of Mining and Technology (CUMT), Xuzhou, 221116, Jiangsu, People’s Republic of China

    Man Zhongyi

  3. The National Joint Engineering Laboratory of Internet Applied Technology of Mines, China University of Mining and Technology (CUMT), Xuzhou, 221116, Jiangsu, People’s Republic of China

    Liu Chun & Wei Mingyao

  4. State and Local Joint Engineering Laboratory for Gas Drainage and Ground Control of Deep Mines, Henan Polytech University, Jiaozuo, 454002, People’s Republic of China

    Liu Chun

Authors
  1. Man Zhongyi
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Liu Chun
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Wei Mingyao
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

ZM was involved in writing and editing, polishing, data collection, software, and application. CL was involved in guide, investigation, funding, data curation, and supervision. MW contributed to direction and supervision.

Corresponding author

Correspondence to Liu Chun.

Ethics declarations

Conflict of interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Zhongyi, M., Chun, L. & Mingyao, W. Mechanical characteristics and crack evolution in specimens with double over-excavated cavities: experimental and numerical investigations. Comp. Part. Mech. (2024). https://doi.org/10.1007/s40571-023-00702-x

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s40571-023-00702-x

Keywords

Search

Navigation