# Numerical study on blasting damage of rock with eccentric charge structure

## TL;DR

This study uses simulations to compare how different charge structures affect rock damage during blasting, aiming to improve safety and efficiency in mining.

## Contribution

The paper introduces a numerical analysis of eccentric charge structures and their impact on rock fragmentation and crack propagation.

## Key findings

- Eccentric charges create higher stress on the coupled side, up to 2.29 times that on the uncoupled side.
- Multi-charge layouts improve blasting effectiveness, with optimal configurations depending on the number of charges.
- The influence of eccentric charges is limited, with stress fields converging to concentric patterns beyond a certain range.

## Abstract

To enhance the safety and efficiency of blasting operations in mines, this study numerically investigates the influence of eccentric versus concentric decoupled charge structures on rock fragmentation under constant charge mass. Using ANSYS/LS-DYNA simulations, the distribution of effective stress (ES) and crack propagation patterns around a single borehole were analyzed. Damage evolution was quantitatively assessed through the damage area ratio (DAR) metric. The results indicate that eccentric charges induce an asymmetric stress field, with ES on the coupled side being up to 2.29 times higher than that on the uncoupled side, and promote vertically symmetrical crack propagation with higher crack density near the charge. The influence range of eccentric charging is limited. Beyond this range, the stress field converges to that produced by concentric charging. Compared to a single charge, multi-charge layouts (double/triple) significantly improve blasting effectiveness, with the optimal structure depending on the number of charges: bottom-eccentric for single or double charges, and concentric for triple charges. These findings provide concrete theoretical guidance for designing controlled blasting schemes in engineering applications such as soft rock blasting, presplitting, and roadway excavation in hard rock formations.