Numerical simulation analysis of hole spacing in deep hole pre-splitting blasting of roof cutting and retaining roadway
LI Pei
XIE Ping
ZHANG Wenchao
WANG Mengxiang
HUANG Wenyao
NIU Caoyuan
Abstract：In order to improve the recovery rate of coal resources,alleviate the strain on mining and excavation operations,and prevent geological disasters caused by the presence of reserved coal pillars,the technique of roof cutting and roadway retaining has become as the primary approach for coal mining in mines.To investigate the impact of different blast hole spacing on rock roof cutting during blasting,a dual hole pre-splitting blasting model is established using the finite element simulation software LS-DYNA.The model considers both with in-situ stress and wtihout in-situ stress scenarios.The hole spacing is set to 10 times,12 times,14 times and 16 times the blast holes diameter in turn,and the optimal blast hole spacing is determined through comprehensive analysis of numerical model results,including the effective
stress cloud diagram,effective stress time history curve,and crack propagation between blast holes.Field tests are then conducted based on the selected blast holes.The results show that in-situ stress has an inhibitory effect on blast hole cracks.Under the in-situ stress state,the crack penetration distance between two blast holes is 9 to 11 times the blast hole diameter,which has the best effect and causes less damage to the surrounding rock mass.It is consistent with the field drilling peep results.
Keywords：roof cutting and roadway retainingdeep hole pre-splitting blastinghole spacingLS-DYNAcrack propagation
Publication Date：2023-12-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 1-4,28 )