Study on Water Disaster Prevention and Control Technology under Condition of Extra-thick Coal Seam with Slicing Fullmechanized Caving Mining

摘要

Some coal seams belong to cretaceous strata in the east of Inner Mongolia, China. There are obvious differences of rock characteristics and mechanical properties between Cretaceous and Carboniferous- Permian strata. The overburden failure characteristics of extra-thick coal seam with slicing full-mechanized caving mining are studied through rock mechanics experiment, field observation and theoretical analysis and so on. Water disaster prevention and control method of roof and goaf is put forward under the condition of extra-thick coal seam with slicing full-mechanized caving mining. The final research results include: (1) The rock of cretaceous strata has low strength and soft characteristic, its stability is very poor, cretaceous rock belongs to weak type; (2) Under the condition of extra-thick coal seam with slicing full-mechanized caving mining, the ratio between caving zone and mining height of field observation result is 4.58～4.74, the observation results of two boreholes are close; (3) It is significantly effective to prevent and control water disaster from goaf through roof hole drainage method, coal and rock safety pillar remain method is used to limit mining height under the Tertiary gravel aquifer, which makes the working face exploit safely.