Numerical Simulation And Prediction For Deep Mine Water Inflow In Chaochuan Mine

The 21 coal is mainly extracted in Chaochuan Mine. The Carboniferous thin limestone and Cambrian limestone are distributed in the coal seam floor. The developed karst fissures and rich karst high pressure water lead to frequent water burst accidents in the process of coalmining. At present, the coalmining has been extended to -250 level. The depth increased, so are the dangers by water filling. In order to ensure the normal exploitation of the mine, it's needed to simulate and reproduce the deep karst water flow field characteristics, so as to predict water level dynamics and water inflow under normal coal-mining conditions.Based on a comprehensive analysis of the geological and hydrogeological conditions in Chaochuan coalfield, this paper built up a hydrogeological conceptual model through discussion of the growth and development regularities in a vertical way of the karst in Chaochuan coalfield. By adopting the internationally prevalent Visual Modflow software, the numerical simulation model of groundwater seepage is built up on the basis of the data including water level observation and water displacement in Chaochuan coalfield from Jan. 2004 to Dec. 2007 for 4 years. Through model test and parameter identification, the numerical simulation model is established with actual hydrogeological conditions, and stable and reliable. And it has been compared with the mathematical model established by making use of gray system theory. The prediction results show that: (1) The uneven space of hydrogeological condition is more intense in deep karst aquifer. Bounded by the inclined well, the karst aquifer permeability and water transmissivity are both strong on the west, yet very weak on the east.(2) The normal mine water inflow under the condition of the existing mining in Chaochuan coalfield is 1152.36m3/h and the maximum is 1843.776m3/h, which provide scientific basis for the mine designing mine drain equipment and making plans to prevent and cure water in the future.