Research On Groundwater Drainage Optimal Management Model Based On Coal Mining

Coal is the main energy in our country. In order to reduce the pressure from the water inrush aquifers, it is necessary to drainage during mining so that groundwater level declines continuously, which leads groundwater resources and even ecological environment system to be seriously damaged. As a result, how to both ensure coal mine safety production and protect groundwater resources in drainage process has an important practical significance on coal mining sustainable development.Based on consulting foreign and domestic relevant literatures, the west wing of Panbei coal mine in Huainan, Anhui province has been taken as the research case. Geological and hydrogeological conditions of Huainan mining area and Panbei coal mine have been analyzed comprehensively, and especially, the hydrogeological conditions under the seam floor of coal group A in west wing of Panbei coal mine have been analyzed. Furthermore, through reasonably generalizing the hydrogeological conditions of C3I group limestone aquifer, the corresponding hydrogeological conceptual model and its three-dimensional mathematical model have been established. And the hydrogeological parameters of different blocks in the study area have been obtained by groundwater numerical simulation.In order to further solve the safety mining problem of coal group A in west wing of the field in future, combined with the simulation model, the groundwater drainage optimal management model of C3I group limestone aquifer in west wing has been established through taking the minimum drainage volume as goal, and it simultaneously satisfies constraint conditions such as the safety mining water level, the single-borehole drainage volume and the largest ability of mine drainage. According to the prevention and control measures of limestone water disasters, including aquifer drainage, grouting reinforcement for coal floor and so on, four limestone groundwater drainage optimal management schemes have been designed. For their respective optimal management model, by using simplex method and programming calculation, the corresponding optimal drainage volume and water distribution values of different drainage boreholes have been gotten.The optimal calculation results show that all of the follwing measures could realize the safety mining of coal group A in the next five years such as continue to arrange new boreholes westerly, make C31and C32limestone under the seam floor of coal group A with grouting reconstruction, or combine the both. But starting from the protection of groundwater resources, the most effective measure is to make the thin-layers under the seam floor with grouting reconstruction while also increase boreholes westerly and distribute their drainage values reasonably.