Dynamic Response, Damage, and Particle Transport of Cut Blasting Under a Biaxial Initial-Stress State

Cut blasting in deep excavations occurs in rock masses subject to unequal initial stresses. This study compares two SPH–FEM simulations of the same cut-blasting problem: S35–22, a prescribed biaxial initial-stress state derived from mine-provided field stress records, with horizontal and vertical components of 35 and 22 MPa, respectively, and S0, a zero-preload numerical baseline. The analysis considers equivalent-stress histories and sectional RHT damage over 0–20 ms, the cumulative initial mass of rock SPH particles first observed at D = 1 and its interval-average increase over 0–40 ms, and finite-window cumulative first-crossing mass evaluated through 40 ms. The comparison characterizes the response of the prescribed S35–22 state relative to S0 within the stated observation windows.