Numerical Simulation of Pre-splitting Blasting in Steep Hard Thick Coal Seam

The second1 coal seam of main mining coal seam in Xingtai coal mine is steep hard thick coal seam,because the strength of the coal and rock mass in the second1 coal seam is very high and they are large blocks,it brings a big difficulty to the coal mining of the second1 coal seam.To the actuality that the second1 coal seam is hard to mine,the dynamic analysis ANSYS /LS-DYNA was used to simulate to deep-hole pre-splitting blasting of the second1 coal seam,according to the rule that the peak of tensile stress change curve of broken bad element reach the tensile strength of coal,the pre-splitting blasting parameters are optimized.Setting the holes spacing are respectively3.0 m,3.5 m,4.0 m in the progress of simulation,then make the parameters,the appropriate loaded structure and the way of initiation.Through the numerical simulation of the three kinds of schemes,finally the optimal blasting parameters when the hole spacing is 3.5 m.