Study On Water Bursting Mechanism Of Confined Water In Pioneer Open - Pit Coal Mine

Water-inrush from coal seam floor is a disaster that common in coal mining above the confined aquifer, seriously affecting the safe production of coal mine In recent decades, many scholars have made a large number research on the water-inrush mechanism and water-inrush from coal seam floor, Achieved fruitful results, the water pressure mining work has played a guiding role. Research but inclined water inrush in opencast mine area is still relatively small. Therefore, this paper has researched on the water-inrush mechanism of the opencast’s inclined coal seam floor based on theoretical analysis and numerical calculation. So in this paper, we used theoretical analysis and numerical calculation to systematic research on the water-inrush mechanism of the opencast’s inclined coal seam floor, and obtained some achievements as follows:(1) On the basis of opencast’s inclined coal characteristics of opening, the corresponding mechanical models are set up, which can calculate the stress at any point of the plate.(2)According to the characteristics of opencast’s inclined coal, analyzed the failure process of coal seam floor of Coulomb with the Mohr theory and the principle of hydraulic splitting.(3) Based on the Mohr-Coulomb yield criterion and the Formula of water inrush coefficient, obtain a new method to evaluate and predict water-inrush from coal seam floor. And use it to predict water-inrush of some important point of the Xianfeng mine in Yunnan Province. Then compare with the result of the Formula of water inrush coefficient, find that some areas non-water inrush with the result of the Formula of water inrush coefficient, but it is possible to water inrush use the new method of this paper.(4) Based on the occurrence characteristics of the pioneer of open pit coal mine coal seam, using FLAC3D software, three dimensional numerical model is built to simulate and analyze the open-pit mine, at different excavation depth of coal seam floor, the variation law of stress, displacement, failure characteristics of floor water inrush, that is easy to position near the slope toe excavation surface, and the results of income the results of the numerical simulation and the new evaluation methods are simple contrast, validate rationality of the income evaluation method. The research achievements provide an important directive function to the opencast inclined coal seam safety mining above a confined aquifer.Study on evaluation method of water inrush from coal floor income of this paper can be used to guide on the confined aquifer of opencast’s inclined coal seam mining work.