Site Stability Evaluation and Environmental Impact Analysis on the Working Face of Old Coal Mine in Pangzhuang

Based on structural geology, stratum and lithology, seismic, hydrogeology andgeotechnical engineering geology, the coal seammining data about the working face of old coal mine in Pangzhuang has been analyzed in this paper. The residual deformation of ground surface about the industry square in this coal mine has been predicted and calculated through using the probability integral method of residual deformation, its site stability has been evaluated. And then, the environment impacts from the coal miningin Pangzhuang have been analyzed. The coal mining in Pangzhuang has greatly impacted the local geological environment, including the destructionson original topography, surface water, engineering geological and hydrogeological conditions. In Pangzhuang coal industry square, the maximum residual incline value (im) about the inflection points (that are used for calculating the deformation boundary) of maximumresidual deformation is 3.02~3.28 mm/m, which is larger than 3.0 mm/m, suggesting that the residual incline(im) may pose a hazard locally to the proposed construction project.In this paper, the risks of geological hazard in the proposed project area can be divided into three zones. The No.Ⅰand No.Ⅱ zones have low and medium dangerous respectively, which are appropriate and basic suitable sites. But, the No.Ⅲ zone has big risk, which has bad site suitability and needs to treat its foundation through engineering methods. This evaluation work provides the site safety assurance to the construction projects of Huamei 2×300MW(CFB) unit for Xuzhou mining group, meanwhile, it improves the land comprehensive utilization in Pangzhuang coal mine, providing a solid support for the rational utilization of precious land resources.