Study on Mine Strata Pressure Behavior Law of Backfill and Roof Falling Mining Method

According to the practices on the roof falling and backfill mining in Zhaizhen Mine, the mine strata pressure behavior law of the No.7203E Up backfill min ing face and No.7203E Down fully mechanized coal mining face with a backfill compacted rate of 40%7 0% were compared and analyzed.The mine strata pressure beha vior features of the different mining methods were obtained.The study showed that under the backfill compacted rate of 40%7 0%, the backfill coal mining face and the r oof falling coal mining face would be same and both would have obvious periodic weighting features.The weighting interval of the backfill coal mining face would be lon ger than the roof falling coal mining face and the dynamic load coefficient and the weighting strength of the backfill coal mining face would be smaller obviously.The bas ic roof weighting strength of the backfill coal mining face would be obvious. Especially under the condition of the coal mining with complex roof, the coal spalling occurre d in front of the powered support would be serious and the roof control at the no support roof zone needed a high attention.