Numerical simulation of rock mass vibrations induced by nearby production blast

Abstract

It is of importance to understand the effect of production blasts on the surrounding rock formations in underground mines. This study presents a numerical procedure to simulate stress waves resulting from nearby production blasts. First, the damping coefficient and peak borehole pressure are calibrated using a dynamic numerical model of a single blast hole. The resulting time-varying particle velocities in the surrounding rock mass at the specified points are calculated. These are then used as input parameters in a three-dimensional mine-wide model, considering a positional relationship between the blast hole and the specified points on the wall rock. The mine-wide model encompasses a fault running parallel to a steeply dipping, tabular ore deposit. Dynamic analysis simulating the effect of production blasts is conducted after the extraction of mining blocks with static analysis. In this study, variations of stresses along the fault due to blast-induced stress waves are examined. Results demonstrate that the developed methodology can reasonably simulate stress changes induced by stress waves on the fault. The methodology considers blast sequences and time-varying blast loads that vary according to the positional relationship between the blast holes and the specified points on the wall rock.