AbstractThe peak load on a borehole wall is a key parameter in calculating the blasting failure range and in numerical simulations of nonfluid–structure coupling. In this study, the characteristics of the peak load in water-coupling blasting are studied theoretically and numerically. First, the interaction between a waterborne shock wave and a borehole wall is analyzed theoretically to reveal the main factors in the peak load on the borehole wall. Then, based on the theoretical calculations and the principle of dimensional homogeneity, a calculation model for the peak load is determined, and a numerical simulation of fluid–structure coupling is carried out to obtain the peak load under different conditions in two types of water-coupling blasting. The theoretical and numerical results are compared, and a correction coefficient is introduced to optimize the theoretical model. The results showed that the peak load increases approximately as a power function with increasing rock wave impedance and decreases approximately as a power function with increasing decoupling coefficient. Furthermore, it is concluded from statistical analysis that the correction coefficient is linearly proportional to the decoupling coefficient. In summary, a method for calculating the peak load on a borehole in water-coupling blasting is proposed, and it is verified against existing stress test data from water-coupling blasting.