Research On Failure Mechanism And Application Of Surrounding Rock About Thin Bedrock Coal Seam With Threat Of Waterinrush

It is very important to develop the coal resources covered by thick unconsolidated layers in Easter region. This can ease the strain on coal resources of eastern china. However, research on the failure law of thin-bedded roof strata with thick unconsolidated layers is one of key problems to control mining safety under the thick unconsolidated layers of thin-bedded roof strata. Based on the evaluation of hydro geological conditions, field observation, laboratory similarity simulation experiment, numerical simulation, the thesis adopts theories of material mechanics, elastic mechanics, damage mechanics and so on, and applies fractal theory, artificial intelligence forecasting methods to study comprehensively the failure law for the threat of water-inrush causing by thick and loose thin-bedded roof strata under the influence of mining, which mainly includes the failure mechanism and feature of coal seam roof, evolution characteristics of overlying strata failure fracture, strata-pressure behavior of bedrock under different conditions, overburden rock damage height and coal floor failure depth. Besides, the thesis deduces the calculation formula for limited span of main roof primary fracture, instability judgment basis of three hinged arch, the calculation formula of roof displacement. Furthermore, the thesis establishes fractal damage model of evolution characteristics for overburden fracture and prediction models of damage height for overburden fracture and failure depth for coal seam floor respectively, which provide theoretical basis for the further study of rock failure mechanism of thin bedrock seam and develop the basic theory of mine pressure. The research results was used in condition that mine water inrush threats thin seam in Zhaogu mine, which has achieved remarkable economic benefit.