Research On Mechanism Of Preventing Floor Water Inrush In Confined Water Mining By Solid Backfill Mining

The mining conditions and circumstances of coal resources in China are becoming increasingly complex,especially being seriously threatened by water disasters.During the mine extraction,the floor is bound to be deformed and damaged under the influence of mining stress and confined water,etc.If the failure depth of the floor reaches the confined aquifer,the working face will suffer water inrush disaster.And solid backfilling in the aspects of prevention and control of rock instability has significant advantages,is the core of the coal mining science and green mining technology,one of the confined water solid filling mining floor of deformation and failure mechanism of prevention and treatment of floor water inrush is not yet clear,therefore,in order to reveal the confined water inrush mechanism of prevention and control of solid filling mining based on the field investigation and theoretical analysis,laboratory test and numerical simulation of the integrated research methods,summarizes the causes and affecting factors confined water mining of coal seam floor water inrush,reveals the controlling role of filling mining of floor deformation,tested the Yellow River sediment filling materials on mechanical properties,The deformation and failure characteristics of backfill mining floor over confined water were obtained,the failure depth of backfill mining floor over confined water was calculated,and the engineering design method of backfill mining to prevent water inrush from floor over confined water was put forward.The main research results are as follows:(1)The formation reasons of floor water inrush in coal seam mining over confined water are summarized,and the main factors affecting floor water inrush in coal seam mining over confined water are summarized;The deformation and stress distribution of floor under backfill mining and caving mining are compared and analyzed,and the control effect of backfill mining on floor deformation is revealed.The compressive mechanical properties of the filling material mainly composed of the Yellow River sediment were tested,and the compressive stress-strain relationship of the filling material was obtained by fitting.(2)combined with solid packing material stress-strain relations,solid material filling simulation method is given,and builds the confined water filling mining floor damage numerical model,studies the filling ratio by filling mining with water pressure plate deformation,stress distribution and the influence law of damage range,reveals the confined water filling mining floor deformation and failure characteristics.(3)Based on the stress distribution characteristics of stope floor in backfill mining,the floor was regarded as a semi-infinite body,and the stress distribution law of backfill mining floor under the influence of mining was studied.The plastic mechanics model of floor failure in backfill mining over confined water was established.The influence of filling ratio and water pressure on floor failure range was analyzed,and the failure depth of floor failure in backfill mining over confined water was determined.(4)The engineering design method of preventing and controlling floor water inrush over confined water by solid backfill mining was proposed,the filling rate index of the test area was given,and the monitoring and feedback system of backfill quality and floor stability was designed.There are 83 figures,12 tables and 104 references in this paper.