In the process of underground metal mining, the use of traditional upward fan‐shaped holes is limited by rock drilling quality, low blasthole utilisation rate and inefficient mining. According to the conditions at the Gongchangling iron ore deposit, a large‐span parallel‐hole ore‐dropping technology was adopted. The main feature of this technology was to increase the width of the mining roadway. To study ore migration caused by long‐span parallel‐hole blasting in the Gongchangling iron mine, a discrete element software package, PFC2D, was used to numerically calculate the effects of parallel‐hole blasting with three spans and three hole spacings to complete the calibration of the parameters of microscopic particles. Research findings indicate that: First, following parallel‐hole blasting, the loose body poured into the mining roadway, the displacement in the middle was large, and the displacement on both sides of the body was small; second, the influences of two factors, the span of the mining roadway and the blasthole spacing, on the contact characteristics of the particles were analysed; third, the blasting force chain of parallel holes with different hole spacings and spans showed anisotropy, with the contact force slightly larger in the vertical direction than the horizontal direction.
Luo et al. (2026) studied this question.