Physical simulation analysis of coal rock mechanics characteristics and shock wave effects in Liuxiang coal mine

The controllable shock wave technology has broad application prospects in coal mining. In this paper, firstly, a shock wave energy testing platform is built. Then, controllable shock wave energy screening experiments were conducted, and the pressure evolution characteristics under different energy containing rod impact conditions were analyzed. Thirdly, the physical model samples were subjected to impact in an experimental tank without confining pressure, and the impact of the experimental results on the site was analyzed. Results show that: (a) The 80 kJ energetic rod generates a peak shock wave of 16.5 MPa at 341.4 us and the 60 kJ energetic rod at 335.4 us, respectively; (b) The peak value of the shock wave of the 40 kJ energetic rod has decreased by more than twice. But the peak pulse width and main pulse width are greatly increased, resulting in stronger visual impact. (c) The average porosity increased from 15.24 to 15.62%. The average permeability has increased from 1.75 × 10⁻³ to 2.47 × 10⁻³ μm², and the fractures on the rock core cross-section are well-developed. (d) The mechanical measurement results showed that the compressive strength of sandstone decreased by 20.36% after the experiment; (e) The various indicators of the 80 kJ energetic rod are more balanced and can effectively crack the sample.