Abstract: In view of damage on backfill body resulting from the deep-hole blasting in the two-step mining process with subsequent filling mining method,and based on the rock mechanical properties and blasting parameters in Wuzhuang Iron Mine,the fan-patterned deep hole blasting model with different hole-bottom burden was established based on the LS-DYNA,and the related numerical simulation was carried out.The simulation results indicated that the vibration velocity and effective stress gradually decreased with the increase of the hole-bottom burden,and the damage of blasting on the filling body was reduced.The numerical simulation results showed that field experiments on fan-patterned hole blasting parameters with 0.5m hole-bottom burden were carried out,and VS150 three-dimensional laser scanning detection system was used to realize measurement.After processing and analyzing the scanning data,it is concluded that the surface of the filling body was smooth and no collapse occurred,thus the optimized fan-patterned hole blasting parameters was obtained to guide the underground blasting construction in the future.

Key words: Two-step mining, Blasting parameters optimization, Backfill, Numerical simulation, Engineering practice