Study on influence rules and evaluation criteria of groundwater affected by mining in unconsolidated aquifers in Shendong Bulianta coal mine

The evaluation method of groundwater affected by mining in unconsolidated aquifers cannot be applied in Shendong coal mining area. Aimed at this problem, the paper has taken Bulianta coal mine as an example, analyzed the influence rules of groundwater hydrodynamic field affected by mining. It is concluded that mine water is the main factor causing the change of the relationship among atmospheric precipitation, surface water and groundwater. Then three evaluation criteria were put forward to evaluate the influence rules on groundwater affected by mining from the aspects of ecological water level and the failure of unconsolidated aquifers and the groundwater loss. The results show that the disturbance criteria of groundwater ecological water level in unconsolidated aquifers in Bulianta coal mine are almost more than one by 2012 and the ratio of mining to disturbance reaches up to 92%, which means mining has a great damage to the ecological water level. The cracks caused by mining develop directly in the unconsolidated aquifers, so that 8% of the aquifers are completely destroyed leading to lack of groundwater storage capacity. Because of the reuse of mine water, the groundwater loss is reduced to 8.5%, indicating that the utilization of mine water is an effective measure to reduce groundwater loss.