Abstract: In the two-step stope with subsequent filling,medium-deep hole blasting has an impact on the filling experience,so it is of great significance to study the blasting response of backfill to ensure mining safety.Through the field blasting vibration velocity test,the attenuation equation was obtained by fitting the monitoring data.At the same time,ANSYS/LS-DYNA finite element software was used to conduct numerical simulation analysis on different differential time and different stemming length schemes.The results showed that:① the calculated results of attenuation equation were basically consistent with the numerical simulation results,and ANSYS/LS-DYNA software used to simulate the influence of blasting on the stability of backfill could obtain ideal results.② With the increase of the differential time from 19 ms to 25 ms,the maximum effective stress and peak velocity at the interface between the stope and backfill firstly decrease and then increase.When the differential time is 23 ms,the maximum value reaches the minimum value,which meets the specification requirements and has the least influence on the backfill.③ Based on the original mine blasting parameter scheme,four kinds of stemming length schemes were designed.By analyzing the maximum effective stress and peak velocity of the interface between the mine room and the backfill,when the stemming length ls1~ls5 was 2,4,2,5,4 m respectively,the blasting had the least influence on the backfill and had the best vibration reduction effect.The study results can be used as a reference for the design of blast hole parameters in similar mines.

Key words: filling mining,ANSYS/LS-DYNA,stability of backfill,blasting vibration speed,differential time,stemming length