Study on mine strata behavior with full backfill effect of paste backfill in coal mine

In order to study a full backfilled rate affected to the overburden strata movement law of the coal mining face,based on Daizhuang Mine as the engineeri ng background,a test was firstly conducted on the backfill material features.Then the Midas/GTS-FLAC~(3D) coupling simulation technology was applied to establish th e numerical analysis model of the paste backill mining in No.2351 coal miming face and to simulate and study the mine strata behavior when the full backfilled rate of t he coal mining face was 0、80%、85%、90%、95% and 100%.The results showed that the backfill body could effectively restrain the movement and deformation of the overburden strata above the coal mining face.The overburden strata above the backfilled coal mining face would generally cause the cracking zone and the bending su bsidence zone.The higher backill rate, the lower support pressure would be and the peak stress location of the front coal body and the backfill body behind would be mo re closed to the coal mining face.When the backill rate of the coal mining face was 100%,in comparison with the non backfill mining,the plastic zone width of the coal m ining face would be 5% of the previous width and the support pressure would be below 50% of the previous pressure. Therefore,the backfilled effect of the overburden st rata above the coal mining face was obvious and the coal mining face should be possibly backilled to the roof in the engineering practices to ensure the backfill quality and the mining safety. .