【作者】 李毅；

【导师】 刘博；

【作者基本信息】 中国矿业大学 ， 水利工程（专业学位）， 2022， 硕士

【摘要】 研究区露天煤矿位于敦德淖尔水源地,随着矿坑向西北方向推进,距离辉特淖尔和敦德淖尔两湖泊越来越近,因此面临煤矿安全开采与湖泊水资源保护双重问题。本文基于研究区近湖露天煤矿水文地质调查工作,分析了研究区潜水地下水流特征,在重点研究区开展了潜水含水层抽水试验,利用抽水试验数据计算获得相关水文地质参数,运用GMS数值模拟软件建立了研究区潜水含水层地下水流模型,并对模型参数进行了识别与校正,在此基础之上,设计矿区扩建后多种开采控水措施方案,预测分析各方案下的控水效果,并对比评价出最佳控水方案。论文主要取得以下研究成果:(1)研究区第四系全新统、上更新统含砾细砂含水层(即区域潜水)为矿区主要直接充水水源,也是矿坑开采地下水疏干目标含水层。矿区西北侧分布的辉特淖尔和敦德淖尔两个湖泊与研究区潜水具有直接的水力联系,因此湖水为矿区间接充水水源。(2)研究区内潜水水位标高为930～970m,湖水标高929.5m,潜水主要为大气降水入渗补给和地下水侧向补给。天然条件下,部分地下水自盆地四周向中心汇集,泄于湖泊之中,部分则由北西方向排泄至区外;由于露天矿开采,使含水层结构发生改变,同时受矿坑边界疏干井抽排地下水,导致靠近露天煤矿范围内的地下水流场发生改变,造成矿坑边界局部地下水位降低,使地下水向开挖的矿坑内径流排泄。(3)利用设计的8个水文地质钻孔,开展了共计3组、8次降深、历时6660分钟的抽水试验及水位恢复试验。利用抽水试验数据计算得到潜水含水层的渗透系数为0.42～3.45m/d,给水度为0.117～0.191,抽水试验影响半径为20.42～32.78m,含水层单位涌水量为0.15～0.41 L/(s·m),均属于中等富水性。这些水文地质参数为地下水流数值模型提供有效参数。(4)基于研究区水文地质条件及潜水流动特征,构建了地下水流水文地质概念模型,包括确定模拟范围60.12km~2,给定模型内、外边界条件,对湖泊区和非湖泊区分别采用有限差分和有限单元方式进行网格剖分,将模型分为两个不同水文地质参数区,模型汇源项考虑了降雨、蓄水池、疏干井、湖泊、排水沟,利用观测孔水位数据对模型进行识别与验证,结果显示:模拟水位与实测水位数据基本相符,变化趋势一致;地下水流场符合实际情况,模型精度较高。(5)结合疏干排水与帷幕注浆控水措施,设计了6种不同控水方案,方案中考虑了疏干井数量、抽水量、帷幕位置、帷幕尺寸。通过模拟预测不同控水方案下10年的地下水流场与湖水水位变化,讨论各方案下湖水补给量、排泄量、总变化量、水位降幅、地下水疏排量、地下水水位降低幅度,对比评价得出仅考虑湖水水位降幅及地下水排放量时,方案5为最佳方案,方案3次之;同时考虑帷幕注浆及疏干井排水成本时,方案3为最佳方案。论文研究成果可为研究区露天矿安全开采与湖泊水资源保护提供科学依据,具有重要的理论意义和实用价值。该论文有图93幅,表21个,参考文献101篇等。更多还原

【Abstract】 The open-pit coal mine in the study area is located in the water source area of Dunde Nur.With the advancement of the pit to the northwest,it is closer and closer to huite Nur and Dunde Nur lakes.Therefore,it faces the dual problems of coal mine safety mining and lake water resources protection.Based on the hydrogeological investigation of Jinhu open pit coal mine in the study area,this paper analyzes the characteristics of phreatic groundwater flow in the study area,carries out the pumping test of phreatic aquifer in the key study area,calculates and obtains the relevant hydrogeological parameters by using the pumping test data,establishes the groundwater flow model of phreatic aquifer in the study area by Using GMS numerical simulation software,and identifies and corrects the model parameters,Design a variety of mining water control measures after the expansion of the mining area,predict and analyze the water control effect under each scheme,and compare and evaluate the best water control scheme.The main achievements of this thesis are as follows:(1)The Quaternary Holocene and upper Pleistocene pebbly fine sand aquifers(Area diving)in the study area are the main direct water filling source in the mining area,and they are also the target aquifers for groundwater drainage in pit mining.Huitenaoer and Dundenaoer lakes distributed in the northwest of the mining area have direct hydraulic connection with the phreatic water in the study area,so the lake water is the indirect water filling source of the mining area.(2)The elevation of phreatic water level in the study area is 930 ～ 970 m,and the elevation of lake water is 929.5m.Phreatic water is mainly supplied by atmospheric precipitation infiltration and groundwater lateral supply.Under natural conditions,some groundwater collects from the periphery of the basin to the center,discharges into the lake,and some discharges from the northwest to the outside of the area;Due to the open-pit mining,the aquifer structure is changed,and the groundwater is pumped by the drainage well at the pit boundary,resulting in the change of the groundwater flow field within the range close to the open-pit coal mine,resulting in the reduction of the local groundwater level at the pit boundary and the discharge of groundwater to the inner diameter of the excavated pit.(3)Using the designed 8 hydrogeological boreholes,a total of 3 groups,8drawdowns and 6660 minutes of pumping test and water level recovery test were carried out.According to the calculation of pumping test data,the permeability coefficient of phreatic aquifer is 0.42～3.45m/d,the water yield is 0.117～0.191,the influence radius of pumping test is 20.42～32.78 m,and the unit water inflow of aquifer is0.15～0.41L/(s·m),all of which belong to medium water yield.These hydrogeological parameters provide effective parameters for groundwater flow numerical model.(4)Based on the hydrogeological conditions and phreatic flow characteristics of the study area,the hydrogeological conceptual model of groundwater flow is constructed,including determining the simulation range of 60.12km2,giving the internal and external boundary conditions of the model,meshing the lake area and non Lake area respectively by finite difference and finite element method,and dividing the model into two areas with different hydrogeological parameters.The catchment term of the model considers rainfall,reservoir,drainage well,lake and drainage ditch,The results show that the simulated water level is basically consistent with the measured water level data,and the change trend is consistent;The groundwater flow field is in line with the actual situation,and the accuracy of the model is high.(5)Combined with drainage and curtain grouting water control measures,six different water control schemes are designed,in which the number of drainage wells,pumping capacity,curtain position and curtain size are considered.By simulating and predicting the groundwater flow field and the change of lake water level in 10 years under different water control schemes,the lake water supply,discharge,total change,water level drop,groundwater drainage and groundwater level drop under each scheme are discussed.The comparative evaluation shows that scheme 5 is the best scheme and scheme 3 is the second when only considering the decline of lake water level and groundwater discharge;When considering the cost of curtain grouting and drainage of drainage shaft,scheme 3 is the best scheme.The research results of this thesis can provide a scientific basis for the safe mining of open-pit mines and the protection of lake water resources in the study area,and have important theoretical significance and practical value.There are 93 figures,21 tables and 101 references in this thesis.更多还原