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In this paper, the mechanism of pre-splitting was analysed using both theoretical and numerical methods. An analytical approach was derived based on the thick-wall cylinder theory. Numerical simulation of pre-split blasting of a two adjacent blast-hole bench was conducted using FLAC3Dsoftware. The sequential loading stages of explosive and stress wave were simplified to a triangular shape pulse and applied to the inner wall of blast-holes. Blast wave fronts and plastic zones were monitored in different elapsed times after detonation. Numerical findings show that collision between the two adjacent stress waves induces a tensile wave, playing the key role in pre-splitting.

This paper examines the hydrodynamic problem of a two-dimensional symmetric and asymmetric wedge water entry through freefall motion. The gravity effect on the flow is considered and because of precise simulation close to the real phenomenon, the oblique slamming is analyzed. The defined problem is numerically studied using SIMPLE and HRIC schemes and by implementing an overset mesh approach. In order to evaluate the accuracy of the numerical model, the present results are compared and validated with previous experimental studies and showed good agreement. The results are presented and compared for each symmetry and asymmetry in different deadrise angles, drop heights and heel angles. Based on a comparison of the measured vertical acceleration of the experimental wedge data, it is determined that the proposed numerical method has relatively good accuracy in predicting the slamming phenomenon and wedge response. The influence of viscous regime on water entry simulations is investigated, in according to results, effect of viscosity is negligible. Results show that the heel angle dramatically affects the wedge dynamics, pile-up evolution, and pressure distribution. These results suggest evidence for a complex interaction between geometric parameters on the water entry of rigid wedges, which could finally develop our understanding of planing vessels operating in real sea conditions.