Application and study on technology of fully-mechanized top coal caving mining face passing through mine abandoned roadway

According to the support pressure of the advanced mining affected to the fully-mechanized top coal caving mining face passing through the mine abando ned roadway, a scope expansion of the plastic zone and broken zone were occurred in the surrounding rock of the mine abandoned roadway and large area roof falling and spalling problems were easily occurred. A FLAC3 Dsoftware was applied to the comparison analysis on the surrounding rock stability of the mine abandoned roadw ay under three support methods of the timber support, bolt support and high water content material backfill during coal mining. The surrounding rock stress, the mine ro adway deformation and the plastic zone distribution features were obtained under the three support methods. The high water content material backfill was finally determ ined as the optimized support method. Based on the features of the high water content backfill material with a different water and cement ratio, a construction plan of th e high water content material backfill was set up and a backfill industrial trial of the fully mechanized top coal caving mining face passing through the mine abandoned「 oadway was conducted. The results showed that during the coal mining face passing through the mine abandoned roadway, the working resistance of the hydraulic pow ered support was only increased by 3.5%. After the coal mining passed through the mine abandoned roadway, the pressure of the hydraulic powered support was recov ered to the normal value, there was no abnormal mine strata behavior occurred and the backfill effect of the abandoned roadway was excellent.