Feasibility Evaluation Of Depressurizing From Taiyuan Formation Limestone Water Of Sector Ⅷ In Taoyuan Coal Mine

Based on the low exploration degree and complicated hydrogeological conditions of high water temperature, high water pressure and anomalous water quality of Taiyuan Formation limestone in the sector VIII, the paper carried out water discharge trial. By means of data analysis, hydrochemistry analysis, numerical simulation and comprehensive analysis, combined with drilling and geophysical exploration results to evaluate the feasibility of depressurizing of Taiyuan Formation limestone aquifer in the sector VIII, then preferred water prevention measures of10coal seam floor in the sector VIII. The main results achieved were as follows:1. From the analysis of drilling data, fissure cave is develop and water quantity is abundant in segments L1-L4limestone of the Taiyuan Formation limestone, which is the main aquifer and source of water of the mine. The thickness of L1-L4limestone is33.0m and stable, with hydraulic discharge is0.422-0.6621/s·m, permeability coefficient is1.512-1.856m/d. The water pressure is high (≥4MPa) and rich in quantity durning making hole down the mine, belongs to the medium to strong water abundance aquifer.2. The understanding drawn through water discharge trial as listed. Water supplies mainly from three areas in the study area, that is concealed outcrop through the skylight, Ordovician limestone supplies in the fault zone and flow through the regional inter-layer layer distant supplies. F2fault is Ordovician limestone supply channel, the DF5fault performances the hydraulic conductivity fault. The sector VIII and the mine region can be regarded as two separate hydrogeological unit for there is no hydraulic connection between them.3. The hydrogeological parameters drawed down from typical observation wells’ water level data of water discharge and recovery phase, consider the recharge boundary and a three-tiered traffic conditions the regional permeability coefficient is0.73-5.94m/d, with an average of2.50m/d. Hydrogeological parameters showing a certain degree of heterogeneity, belongs to medium-rich water aquifer in the sector VIII.4. Water quality test results from the water discharge trial showed that, the water quality of Taiyuan Formation limestone in the sector VIII was basically consistent to the Ordovician limestone. There was small changes of in water quality, water temperature slightly increased, but the water quality type is still basically the same during the water discharge trial. These indicated that Taiyuan Formation limestone water was close to Ordovician limestone water in hydraulic links.5. The paper simulated change regularity of different drawdown under vary water drainage based on hydrogeological conditions of sector VIII, draw that the water runoff conditions were good, with strong lateral recharge, there was little chance to depressurizing of Taiyuan limestone aquifer in the10th coal seam floor, then proposed water prevention measures of grouting transform backplane aquifer.