Research On Karst Groundwater Numerical Simulation And Wrater Hazard Control Methods In Complex Geological Conditions

Coal seam mining has been seriously threatened by karst water inrush from the seam floor in North China type coal field. Therefore, taking reasonable control methods and measures for karst water hazard on the basis of the analysis of the hydrogeological conditions, and furthermore scientific evaluating the security of coal mining have great practical significance for liberating the coal resources threatened by karst water hazard from the seam floor.Panbei coal mine is located in north wing of Panji anticline, the northern part of the Huainan Coalfield. The hydrogeologic condition of the west wing in Panbei coal mine is complex and coal group A has not been mined for being threatened by karst water hazard from its seam floor.Based on consulting foreign and domestic literatures, the west wing of Panbei coal mine has been studied. The groundwater regime of limestone aquifer, the hydraulic connection among limestone aquifers and the transmissibility of faults have been analyzed on the basis of systematically sorting out the previous abundant hydrogeology exploration data. Simultaneously, by comprehensive analysing boundary property, conditions of groundwater recharge, runoff and discharge and spatial distribution of the aquifer in the study area, the hydrogeological conceptual model and the mathematical model have been established. By using the observation data from dewatering test, the spatial distribution of hydrogeological parameters has been obtained and the groundwater flow model has been constructed after recognition and verification stages.According to the hydrogeologic condition of the study area, several karst water hazard control methods and measures have been put forward, such as drainage, grouting transform and curtain grouting. Based on the recognized groundwater flow model, the future groundwater flow field has been predicted and the effect of different karst water hazard control methods has been synthetically evaluated with critical water inrush coefficient as the threshold.Through comparing, both drainage and grouting transform could shorten the drainage time, and the effect would obviously better by combining the two methods. The curtain grouting method can also shorten the drainage time, but its engineering quantity is huge.