Blast damage zone strength reduction method for deep cavern excavation and its application

Abstract

The drill and blast (D&B) method is widely used to excavate underground spaces, but explosions generally cause damage to the rock. Still, no blast simulation method can provide computational accuracy and efficiency. In this paper, a blast equivalent simulation method called the blast damage zone strength reduction (BDZSR) method is proposed. This method first calculates the range of the blast-induced damage zone (BDZ) by formulae, then reduces the strength and deformation parameters of the rock within the BDZ ahead of excavation, and finally calculates the excavation damage zone (EDZ) for the D&B method by numerical simulation. This method combines stress wave attenuation, rock damage criteria and stress path variation to derive the BDZ depth calculation formulae. The formulae consider the initial geo-stress, and the reliability is verified by numerical simulations. The calculation of BDZ depth with these formulae allows the corresponding numerical simulation to avoid the time-consuming dynamic calculation process, thus greatly enhancing the calculation efficiency. The method was applied to the excavation in Jinping Class II hydropower station to verify its feasibility. The results show that the BDZSR method can be applied to blast simulation of underground caverns and provide a new way to study blast-induced damage.

Graphical abstract

Keywords

attenuation of stress wave / deep-buried underground building / drill and blast / in situ stress

References

[1] Li H B, Xia X, Li J C, Zhao J, Liu B, Liu Y Q. Rock damage control in bedrock blasting excavation for a nuclear power plant. International Journal of Rock Mechanics and Mining Sciences, 2011, 48(2): 210–218

[2] Zhu W C, Wei J, Zhao J, Niu L L. 2D numerical simulation on excavation damaged zone induced by dynamic stress redistribution. Tunnelling and Underground Space Technology, 2014, 43: 315–326

[3] Xie L X, Lu W B, Zhang Q B, Jiang Q H, Wang G H, Zhao J. Damage evolution mechanisms of rock in deep tunnels induced by cut blasting. Tunnelling and Underground Space Technology, 2016, 58: 257–270

[4] Chen M, Ye Z W, Lu W B, Wei D, Yan P. An improved method for calculating the peak explosion pressure on the borehole wall in decoupling charge blasting. International Journal of Impact Engineering, 2020, 146: 103695

[5] Hu Y G, Yang Z W, Huang S L, Lu W B, Zhao G. A new safety control method of blasting excavation in high rock slope with joints. Rock Mechanics and Rock Engineering, 2020, 53(7): 3015–3029

[6] Diederichs M S, Kaiser P K, Eberhardt E. Damage initiation and propagation in hard rock during tunnelling and the influence of near-face stress rotation. International Journal of Rock Mechanics and Mining Sciences, 2004, 41(5): 785–812

[7] Golshani A, Oda M, Okui Y, Takemura T, Munkhtogoo E. Numerical simulation of the excavation damaged zone around an opening in brittle rock. International Journal of Rock Mechanics and Mining Sciences, 2007, 44(6): 835–845

[8] HuY GLuW BJinX HChenMYanP. Numerical simulation for excavation blasting dynamic damage of rock high slope. Chinese Journal of Rock Mechanics and Engineering, 2012, 31(11): 2204−2213 (in Chinese)

[9] Lu W B, Yang J H, Chen M, Zhou C B. An equivalent method for blasting vibration simulation. Simulation Modelling Practice and Theory, 2011, 19(9): 2050–2062

[10] Lu W, Yang J, Yan P, Chen M, Zhou C, Luo Y, Jin L. Dynamic response of rock mass induced by the transient release of in-situ stress. International Journal of Rock Mechanics and Mining Sciences, 2012, 53: 129–141

[11] LuoSYanPLuW BChenMWangG H. Research on the simulation of blasting damage and its mechanism of deep tunnel excavation. Chinese Journal of Rock Mechanics and Engineering, 2021, 40(Sup 1): 2760−2772 (in Chinese)

[12] LengZ DLuW BChenMYanPHuY G. Improved calculation model for the size of crushed zone around blasthole. Explosion and Shock Waves, 2015, 35(1): 101−107 (in Chinese)

[13] WeiDChenMYeZ WLuW BLiT. study on blasting failure zone based on rate-dependent dynamic characteristics of rock mass. Advanced Engineering Sciences, 2021, 53(1): 67−74 (in Chinese)

[14] DaiJ. Dynamic Behaviors and Blasting Theory of Rock. Beijing: Metallurgical Industry Press, 2002 (in Chinese)

[15] Luo S, Yan P, Lu W B, Chen M, Wang G H, Lu A, Liu X. Effects of in-situ stress on blasting damage during deep tunnel excavation. Arabian Journal for Science and Engineering, 2021, 46(11): 11447–11458

[16] Zhao J, Zhou Y X, Hefny A M, Cai J G, Chen S G, Li H B, Liu J F, Jain M, Foo S T, Seah C C. Rock dynamics research related to cavern development for Ammunition storage. Tunnelling and Underground Space Technology, 1999, 14(4): 513–526

[17] Chen S G, Cai J G, Zhao J, Zhou Y X. Discrete element modelling of an underground explosion in a jointed rock mass. Geotechnical and Geological Engineering, 2000, 18(2): 59–78

[18] Hao H, Wu Y K, Ma G W, Zhou Y X. Characteristics of surface ground motions induced by blasts in jointed rock mass. Soil Dynamics and Earthquake Engineering, 2001, 21(2): 85–98

[19] WangWLiX C. Experimental study of propagation law of explosive stress wave under condition of decouple charge. Rock and Soil Mechanics, 2010, 31(6): 1723−1728 (in Chinese)

[20] Deng X F, Chen S G, Zhu J B, Zhou Y X, Zhao Z Y, Zhao J. UDEC–AUTODYN Hybrid modeling of a large-scale underground explosion test. Rock Mechanics and Rock Engineering, 2015, 48(2): 737–747

[21] Zhu J B, Li Y S, Wu S Y, Zhang R, Ren L. Decoupled explosion in an underground opening and dynamic responses of surrounding rock masses and structures and induced ground motions: A FEM-DEM numerical study. Tunnelling and Underground Space Technology, 2018, 82: 442–454

[22] Xie H P, Zhu J B, Zhou T, Zhang K, Zhou C T. Conceptualization and preliminary study of engineering disturbed rock dynamics. Geomechanics and Geophysics for Geo-Energy and Geo-Resources, 2020, 6: 1–34

[23] Zhu J B, Li Y S, Peng Q, Deng X F, Gao M Z, Zhang J G. Stress wave propagation across jointed rock mass under dynamic extension and its effect on dynamic response and supporting of underground opening. Tunnelling and Underground Space Technology, 2021, 108: 103648

[24] Yan P, Lu W B, Chen M, Hu Y G, Zhou C B, Wu X X. Contributions of in-situ stress transient redistribution to blasting excavation damage zone of deep tunnels. Rock Mechanics and Rock Engineering, 2015, 48(2): 715–726

[25] GuoDXiaoW HGuoDLuY. Numerical simulation of surface vibration propagation in tunnel blasting. Mathematical Problems in Engineering, 2022: 3748802

[26] YangJ HLuW BChenM. Determination of the blasting load variation in borehole. In: Proceedings of the 2nd National Academic Conference on Engineering Safety and Protection. Beijing: Chinese Society for Rock Mechanics & Engineering, 2010, 773–777

[27] Zhang Y B, Yang F, Huang L Y. Study on the dynamic responses of tunnel linings with small net distance under bias pressures caused by blasting. Geotechnical and Geological Engineering, 2022, 40(2): 605–615

[28] Li X D, Liu K W, Yang J C, Song R T. Numerical study on blast-induced fragmentation in deep rock mass. International Journal of Impact Engineering, 2022, 170: 104367

[29] Lu W B, Leng Z D, Chen M, Yan P, Hu Y. A modified model to calculate the size of the crushed zone around a blast-hole. The Journal of The Southern African Institute of Mining and Metallurgy, 2016, 116(5): 413–422

[30] Esen S, Onederra I, Bilgin H A. Modelling the size of the crushed zone around a blasthole. International Journal of Rock Mechanics and Mining Sciences, 2003, 40(4): 485–495

[31] Aydan Ö. In situ stress inference from damage around blasted holes. Geosystem Engineering, 2013, 16(1): 83–91

[32] Yang J H, Yao C, Jiang Q H, Lu W B, Jiang S H. 2D numerical analysis of rock damage induced by dynamic in-situ stress redistribution and blast loading in underground blasting excavation. Tunnelling and Underground Space Technology, 2017, 70: 221–232

[33] Yilmaz O, Unlu T. Three dimensional numerical rock damage analysis under blasting load. Tunnelling and Underground Space Technology, 2013, 38: 266–278

[34] ZhangJ H. Study on the attenuation law of explosion stress wave in rock of cylinder charge. Thesis for the Master’s Degree. Taiyuan: North University of China, 2005 (in Chinese)

[35] BaiY. Blasting damage model and numerical test of rock under effect of in situ stress. Dissertation for the Doctoral Degree. Shenyang: Northeastern University, 2014 (in Chinese)

[36] BaiYZhuW CWeiC HWeiJ. Numerical simulation on two-hole blasting under different in-situ stress conditions. Rock and Soil Mechanics, 2013, 34(Sup 1): 466−471 (in Chinese)

[37] ChenMHuY GLuW BYanPZhouC B. Numerical simulation of blasting excavation induced damage to deep tunnel. Rock and Soil Mechanics, 2011, 32(5): 1531−1537 (in Chinese)

[38] MuZ MPanF. Numerical study on the damage of the coal under blasting loads coupled with geostatic stress. Chinese Journal of High Pressure Physics, 2013, 27(3): 403−410 (in Chinese)

[39] YangJ H. Coupling effect of blasting and transient release of in situ stress during deep rock mass excavation. Dissertation for the Doctoral Degree. Wuhan: Wuhan University, 2014 (in Chinese)

[40] Shen Y J, Yan R X, Yang G S, Xu G L, Wang S Y. Comparisons of evaluation factors and application effects of the new [BQ]GSI system with international rock mass classification systems. Geotechnical and Geological Engineering, 2017, 35(6): 2523–2548

[41] Zhang R, Xie H P, Ren L, Deng J H, Gao M Z, Feng G, Zhang Z T, Li X P, Tan Q. Excavation-induced structural deterioration of rock masses at different depths. Archives of Civil and Mechanical Engineering, 2022, 22(2): 81

[42] CaoW GZhaoM HLiuC X. A study on damage statistical strength theory for rock. Chinese Journal of Geotechnical Engineering, 2004, 26(6): 820−823 (in Chinese)

[43] CaoW GFangZ LTangX J. A study of statistical constitutive model for soft and damage rocks. Chinese Journal of Rock Mechanics and Engineering, 1998, 166(6): 628−633 (in Chinese)

[44] ZhangDLiuE LLiuX YZhangGYinXSongB T. A damage constitutive model for frozen sandy soils based on modified Mohr–Coulomb yield criterion. Chinese Journal of Rock Mechanics and Engineering, 2018, 37(4): 978−986 (in Chinese)

RIGHTS & PERMISSIONS

Higher Education Press