庞庄煤矿老采区场地稳定性评价及环境影响分析

基于构造地质、地层岩性、地震、水文地质、岩土工程地质条件分析,以及庞庄煤矿老采区煤层开采资料分析,应用残余变形概率积分法,预测计算了庞庄煤矿工业广场的地表残余变形,评价了其场地稳定性,并分析了庞庄煤矿开采对环境地质的影响。庞庄煤矿开采对地质环境的影响特别重大,其影响主要表现为包括原始地形地貌、地表水、工程地质和水文地质条件的破坏。庞庄煤矿工业广场的最大残余变形量拐点连线(计算边界)处最大残余倾斜值im=3.02~3.28 mm/m > 3.0mm/m,残余倾斜(im)可能对拟建工程局部构成危害。笔者将拟建工程区的地质灾害危险性划分为3 个区。Ⅰ区和Ⅱ区分别为危险性小区和危险性中等区,为适宜和基本适宜场地;Ⅲ区危险性大,场地适宜性差,需地基工程治理。评价工作为徐矿集团华美2×300MW(CFB)机组工程机组建设工程提供了场地安全保证,同时,为合理利用宝贵的庞庄煤矿工业广场土地资源,提高土地综合利用率,提供了坚实依据。

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.