Open AccessNumerical simulation of directional fracturing by shaped charge blasting
Author(s) -
Meng Ningkang,
Chen Yong,
Bai Jianbiao,
Wang Xiangyu,
Wu Wenda,
Wu Bowen
Publication year - 2020
Publication title -
energy science and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.638
H-Index - 29
ISSN - 2050-0505
DOI - 10.1002/ese3.635
Subject(s) - borehole , rock blasting , jet (fluid) , fracture (geology) , roof , computer simulation , explosive material , geology , charge (physics) , shaped charge , stress (linguistics) , rock mass classification , deformation (meteorology) , geotechnical engineering , mechanics , structural engineering , engineering , physics , linguistics , chemistry , philosophy , oceanography , organic chemistry , quantum mechanics
The hard roof leads to large deformation or failure of the entry and poses risks to mining safety. Shaped charge blasting is applied to directionally fracture the hard roof and release mining pressure in this paper. The stress condition around the blasting borehole required to induce fracture propagation is calculated by theoretical calculation and numerical simulation. Evolution of blasting‐induced fractures between adjacent boreholes, main fracture in the shaped charge jet direction and secondary fractures in other directions is analyzed. The reliability of Livemore software of explicit dynamics analysis code (LS‐DYNA) in simulating shaped charge blasting is validated by experimental results. A numerical model is established to reveal the formation processes of the shaped charge jet, disclose the evolution of the equivalent stress and understand the development of the main fractures and secondary fractures between adjacent boreholes. The failure type of the rock mass and the fracture development zone are identified. The results indicate that blasting‐induced fractures mainly initiate and propagate in the shaped charge jet direction between adjacent boreholes. Shaped charge blasting leads to the directional propagation of fractures. The field monitoring results show that shaped charge blasting is able to realize the directional propagation of blasting‐induced fractures and release mining pressure.