Numerical Simulation and Engineering Practice for Optimal Parameters of Deep-Hole Blasting in Sidewalls of Roadway

Abstract

Based on an orthogonal experiment, six main factors influencing the effectiveness of coal blasting, namely coal properties, charge structure, charge weight, and the diameter, depth, and spacing of the blast holes were considered. Major inspection indices such as stress transfer in the rock surrounding the roadway’s walls, stress in the near-field region, and deformation of roadway walls were selected. This paper also studied the effect of deep-hole stress-relief blasting in the sidewalls of roadways through numerical simulation. Therefore, we determined that the optimal combination of factors is to use #3 coal with an 8 kg charge weight, 90 mm hole diameter, 15 m hole depth, 3 m spacing between holes, and a non-coupling coefficient of $$K = 4$$ . The calculation result indicates that this combination optimizes the stress distribution in the sidewalls of the roadway. Peak stress is also reduced, and the stress-relief effect changes obviously. Then, an optimal combination of stress relief was applied to the sidewalls of the roadway in the deep coal, and the effectiveness of stress-relief blasting was validated by numerical simulation and field observation methods that proved remarkably applicable for engineering.