Study on Bench Precision Blasting Delay Time Based on SPH-FEM Coupling Algorithm and Its Field Application
Electronic detonators are widely used in large open-pit mine blasting,using its precise detonation characteris-tics through the setting of a reasonable extension time can effectively improve the quality of blasting,and is of great significance to reduce costs and increase efficiency of mine production.This study employed a Smoothed Particle Hydrodynamics-Finite Ele-ment Method(SPH-FEM)coupled algorithm to establish multiple three-dimensional numerical models of conventional bench sizes in the Barun Mine using LS-Dyna software.Establishment of two-hole and three-hole SPH-FEM three-dimensional models for different inter-hole and inter-row delays under electronic detonator detonation conditions.From the perspectives of particle stress and movement in the rock mass SPH particles,the study investigates the force-induced fragmentation and throw displace-ment characteristics of the rock masses subjected to blasting.The study also focuses on analyzing the deflection angles of the blasting crater for rear-row blast holes under different inter-row delay conditions.Based on the analytical results,the optimal ranges for inter-hole and inter-row delay times are determined.Furthermore,the optimal delay for the specific blasting zone is selected through on-site comparative experiments for validation.The study findings indicate that under the current hole spacing settings in the Barun Mine,precise initiation with electronic detonators achieves favorable fragmentation effects when the inter-hole delay falls within the range of 20～30 milliseconds.When the inter-row delay exceeds 35 milliseconds,initiating the first blast hole provides new free surfaces and throwing space for subsequent blast holes,and stress stability is achieved when the delay exceeds 40 milliseconds.In the on-site validation experiment,the percentage of crushed orebodies with a side length of less than 1 m was 91%in the test area.Compared to non-test blast zones,the proportion of similarly sized rock blocks increased by 14%,indicating a significant improvement in fragmentation efficiency.
NETL
NSTL
万方数据
