Numerical Simulation Study About Mining Influence On Groundwater In Weishan Coal Mine

In recent years, the coal resources have made tremendous contributions tothe rapid development of China’s economy. The coal resources are rich in Shanxiprovince. Although productive forces levels improve continuously through theintegration in recent years, still, the great impact of coal mining on groundwaterenvironment should not be ignored, mainly reflected in the diversion fissurezone caused by the gob areas destroys the impermeable layer of the overlyingaquifer, leads to the leakage of water in the overlying aquifer, changes theconditions of recharge and runoff and draining of the original groundwater flowfield and forms a new groundwater flow field. In this paper, Weishan Coal Mineis used as the main object, numerical simulation is applied to predict the theevolutionary trend of groundwater flow field in the overlying Permian andCarboniferous aquifer, and controlling measures are proposed to the theprevention of groundwater pollution.Weishan Coal Mine is suited in Yuci of Shanxi province. In the process ofcoal mining, to ensure safety in production, the aquifer which contains the coalshould be drained. Thus great water head are formed in the two aquifers after thedrainage of water. Due to the existence of relative intact and continuousimpermeable aquifer, it does not harm greatly to the overlying aquifer, but thediversion fissure zone caused by the gob areas may again build hydraulicconnection between different aquifers. In this study, based on the existingengineering geological and hydrogeological conditions, a conceptualhydrogeological model is built with the GMS which is with the finite elementtheory. After the repeating adjustment of parameters, a good fitting result is obtained. The distribution of flow field of the overlying aquifer is analyzed. Theinfluence of coal mining on groundwater in the early production period (after theexploitation of mining area one) and after the exploitation of coal seam fifteen inthe overlying aquifer, and the change of groundwater flow field in the overlyingfissured bedrock aquifers after2.82and11.7years of exploitation is predictedThe prediction results show that after11.7years of coal mining, the wellsof the overlying aquifer in the simulation area will be subjected to differentdegrees of influence.Based on the prediction of the simulation model, the evaluation results ofthe groundwater flow field, and the relevant methods to protect groundwater, thedetailed measures are proposed to protect the groundwater aquifer, to supplywater to residents, and to make a plan in the tracking and monitoring of theaquifer. To better understand and protect groundwater resources, a detailedmonitoring program is arranged to accurately realize the changes in water tableand water quantity.