Abstract: Peak pressure of borehole wall is an important parameter for blasting parameter optimization and dynamic response analysis of non-fluid-solid coupling explosion shock. Based on theoretical analysis of the interaction between underwater explosion shock wave and borehole wall, a simplified calculation model for the peak pressure of borehole wall in water-coupling blasting is preliminarily determined. Using the fluid-solid coupling dynamic finite element numerical analysis method, the peak pressure of the borehole wall under a variety of water-coupling contour blasting charging conditions is studied, and the results are compared with the theoretical calculation results. The correction coefficient reflecting the influence of underwater shock wave propagation in the confined field and the superposition of transmission and reflection in the interaction between underwater shock wave and borehole wall on the peak pressure is determined. The results show that the characteristics of explosive, decoupling coefficients, and medium conditions of rock borehole wall have significant influence on the peak pressure of borehole wall. Through statistical analysis of the relationship between the decoupling coefficients and the correction coefficients under different conditions of explosive type and the wave impedance of rock, it is found that the correction coefficient increases approximately linearly with the increase of the decoupling coefficient. Based on the calculation model obtained by theoretical analysis and the method for determining the correction coefficients, a simplified method for calculating the peak pressure of borehole wall in water-coupling contour blasting is proposed. The method can fully reflect the comprehensive influence of explosive performance, charge conditions and rock medium conditions on the peak pressure of borehole wall.

Key words: contour blasting, water-coupling, peak pressure, shock wave, correction coefficient