武山铜矿地下水数值模拟与矿坑涌水量预测

地下水数值模拟是矿坑疏干排水设计的基础.该文以江西武山铜矿为研究对象,根据矿区地质构造、地层分布及水文地质条件,对矿区的岩溶-裂隙含水系统进行概化,建立地下水流三维数学模型,结合现场抽水试验资料,采用MODFLOW有限差分法进行地下水模拟,预测矿井在不同设计疏干水平下,地下水流场分布及矿区涌水量大小,为矿山地下水有效防治和安全生产提供依据.     

高村采场矿坑涌水量数值预测

根据马鞍山高村铁矿露天采场地质、构造及水文地质条件,在对矿基岩裂隙含水层介质系统和水动力系统进行分析和概化的基础上,建立了矿区地下水水流数学模型。研究中借助GMS软件对模型进行了数值求解,期间利用矿区地下水位长期观测资料对模型进行识别和验证,根据矿山开采规划设计了2种地下水疏干方案,并建立矿坑地下水疏干涌水量预报模型,对未来开采时刻矿坑涌水量进行数值预测,为矿坑疏干设计提供科学依据。     

基于矿井生产进度疏干条件下三维地下水数值模拟

以陕西大海则煤矿为例,研究了多层含水系统矿区疏干条件下的含水介质和边界条件特征,建立了研究区三维地下水流数值模拟模型,完成了模型识别和验证,并结合大海则煤矿的工况特征和矿井生产过程,以首采区回采工作面月掘进进度为单位,采用丰水期和平水期两种预测方案,依次对各回采工作面地下水位疏降至2号煤底板的涌水量进行模拟和预测。该方法将复杂空间地质体和地下水渗流相结合,准确描述了疏降工程的降水过程,所得结果既充分保证了矿井的安全生产,又加强了地下水资源保护。     

某金矿开采项目矿坑疏排水量预测及环境影响分析

矿坑疏排水量是矿山环境保护及安全生产的重要指标,为了合理预测矿坑疏排水量并探讨其对周边环境的影响,本文以湖北某金矿为例,在充分掌握矿区地质及水文地质特征的基础上,采用符合实际条件的解析法模型结合大气降水汇入量对矿坑疏排水量进行了预测,并分析了矿坑疏排水对周边村庄饮用水、温泉、地表水及生态用水的影响,以期为类似水文地质条件的矿区进行环境保护及安全生产提供依据。     

开采扰动对中关铁矿堵水帷幕稳定性影响的数值模拟研究

注浆堵水帷幕技术在矿山基建和生产期可有效地堵截地下水而被众多大水矿山采用,矿山开采的同时需疏干堵水帷幕内围岩中的地下水,为探究疏干排水后开采扰动对堵水帷幕稳定性的影响规律,以中关铁矿堵水帷幕为研究对象,在详细分析矿区地质资料、帷幕内外水位变化规律的基础上,建立堵水帷幕三维地质、力学模型,采用数值模拟方法,分析疏干排水与开采扰动联合作用对堵水帷幕稳定性的影响。结果表明,堵水帷幕与强渗透性围岩接触区域及刚度与围岩差异较大区域,易形成高应力集中区;疏干排水与开采扰动联合作用对堵水帷幕、堵水帷幕与围岩接触区域应力场分布具有显著影响,矿床开采边界距帷幕越近,影响越显著。研究结果可为堵水帷幕稳定性监测提供依据。     

水-岩耦合作用下边坡岩体渗流二维数值模拟

为了研究岩体渗流及水-岩耦合作用对边坡稳定性的影响,首先基于岩体特征建立等效连续介质模型,然后采用有限元法求解该模型,并利用SEEP/W软件模拟正常水位、暴雨入渗和排水疏干时采区地下水渗流。结果表明：等效连续介质模型可靠性高,地下水二维渗流存在各向异性,且裂隙轴向的水力坡降明显大于裂隙径向;3种工况水力坡降明显区域均为边坡表层、不同岩层交界处及混合Ⅰ岩内;暴雨入渗时水-岩耦合作用导致岩层拉应力增大、孔裂隙扩展,剪切滑移为边坡失稳主要诱发机制,而排水疏干有利于提高边坡稳定性。     

三门峡铝土矿地下水疏排数值模拟

根据三门峡段村-雷沟铝土矿区地质构造及水文地质条件,对寒武-奥陶纪灰岩岩溶裂隙含水系统水文地质模型进行概化,建立地下水流数学模型,采用Visual Modflow有限差分方法模拟地下水位和涌水量,结合抽水试验地下水位观测资料对该模型进行校正和参数反演,利用校正后的数学模型和参数,预测井下采矿设计水平地下水疏干的水位和矿区涌水量变化,为铝土矿安全开采及地下水防治提供可靠依据。     

煤田防治水工程三维数值模型

为了研究复杂地质环境下煤炭井工矿开采防治水工程三维非稳定流模拟计算的理论,以平朔矿区安家岭井工矿防治水工程为例,采用三维有限差分数值模拟理论,建立了平朔矿区安家岭井工矿防治水工程三维数值模型,在对模型进行识别、验证的基础上,按整个矿区疏干和分采区面疏干两种方案,模拟了多层含水层情况下各采区煤矿地下水位疏干到4#煤和9#煤所需的最小抽水量。     

某矿山涌水分析及排水方案比选

水文地质复杂的矿山含水层导水性和富水性极不均一,空间赋存和补给条件复杂,地下涌水的突发性和溃入方式往往始料不及,给矿山建设和安全生产带来严重困扰。以国外某矿山为例,结合区域水文和工程地质条件,预测出矿山最终境界地下水总涌水量为6.5万m3/d,同时对矿区提出2种不同的疏干方案进行技术经济比较。在疏干效果都达到预期效果的前提下,计算出2种方案的工程量和投资额,并对后期运营成本进行比较,最终选定地表降水孔+水平放水孔联合疏干方案。矿床疏干技术的应用不仅使水文地质条件复杂、矿坑涌水量大、长期受水害严重威胁的矿山得以开发,同时也可改善作业条件,降低开采成本。     

露天矿疏干排水的数值模拟优化

露天矿疏干排水的优化是露天矿开采一个很重要的问题。如果疏干排水过早,矿山的初期投入大,资金浪费;如果抽水太晚,或位置选择不当,就有可能会出现水淹区抽水、边坡稳定、湿钻孔爆破等问题,这样不仅会增加开采成本,而且会对矿山的安全生产构成隐患。采用Visual MODFLOW软件对某露天矿地下水进行了数值模拟和疏干排水优化,为该矿地下水疏排取得良好效果打下了基础。     

Assessment of Dewatering Requirements and Dewatering Well Design for an Open Pit Coal Mine in Central Anatolia

The Çeltikçi Coal Basin is a newly discovered coal basin in Central Anatolia where 11 years of open-cut mining has been planned. The bulk of the mining will be conducted below the regional water table; hence, determination of the dewatering requirements and proper design of the dewatering wells plays a critical role. This study (i) defined the dewatering requirements of the open-pit mine, (ii) established a dewatering well design for the area, and (iii) assessed the anticipated impacts of the dewatering activities. For this purpose, a 3-D numerical groundwater flow model was developed using the FEFLOW software. Yearly dewatering requirements were determined under transient conditions. For the dewatering well simulations, two types of dewatering wells were considered: permanent wells located at the open pit boundary that would increase in number as the excavation proceeds and wells located at the periphery of the yearly excavated area that would be operational for about two years. The simulation results indicated that 894 wells were required to satisfy dry working conditions; the average pumping rate throughout the mine life was calculated as 322 L/s. The impacts of open-pit dewatering on groundwater resources were assessed in terms of spring discharge and base flow rates in the nearby Kirmir stream. As a result of dewatering, most of the village water supply springs and fountains will dry up in the area. In addition, the base flow rates to the Kirmir stream will be decreased by 15%.

     

蒙西深部复合水体下高强度安全疏控水开采技术

针对蒙西矿区纳林河二号矿井开采深度大,主采煤层受多层含水层威胁、开采强度大的特点,在确定该矿区水害威胁类型的基础上,采用数值模拟、物理相似模拟和经验类比的方法研究了主采煤层覆岩破坏高度,分析了各含水层的充水规律,提出了复合水体下安全“疏控水”技术方案。研究结果表明：蒙西矿区开采主要防治水问题是复合水体威胁下安全采煤;预计得到纳林河二号矿井3-1煤开采垮落带高度按照垮采比4.5倍选取,裂采比按照15倍选取;提出的复合水体下“疏控水”采煤的总体方案为对于白垩系志丹群含水层采取“顶水开采”的方案,对于直罗组底部砂岩含水层采取“边回采边疏降”的控水方案,对于延安组含水层则采取“钻孔疏干或疏降与回采疏干或疏降相结合、先疏后采与边疏边采相结合”的疏水方案。     

Combined Use of Geostatistics and Multi-Criteria Decision Analysis to Determine New Pumping Well Locations in the Gol-Gohar Open Pit Mine,Iran

Groundwater seepage into open pit mines must be controlled carefully. Slope instability, dewatering of blast holes, and mining operations below the groundwater table are important issues caused by groundwater seepage into the Gol-Gohar open pit mine, Iran. There are several methods to overcome these problems, such as construction of cut-off walls, ditches and sumps, horizontal drains, and pumping wells. Drilling of a new pumping well has several difficulties in which the determination of its location is a major issue. In this study, a stochastic simulation approach called simulated annealing was used to determine the best possible locations for new pumping wells. Three major groundwater variables, including the groundwater level, electrical conductivity, and transmissivity were selected for the geostatistical study. The results of simulations showed reliable correlation (Pearson) between the variables. Comparison of the variograms at different depths of the Gol-Gohar pit mine revealed that the effect of faults intensified with increasing depth. The best potential locations for drilling of new pumping wells were identified by the use of multi-criteria decision analysis performed on the simulation results. This method can be used in other regions with similar hydrogeological settings.     

Modelling of groundwater recovery process for prediction of land settlement in surface mines

A two-dimensional finite element model was used to simulate the groundwater recovery process under various surface mining situations. The simulation results were used to predict the rate at which soil settlement takes place. It was found that the groundwater recovery process is very fast immediately after mine closure and cessation of dewatering programmes; a significant part of mine land settlement can be measured at such times. This paper presents a method for deriving the relationship between the re-establishment of the natural groundwater regime to its equilibrium position as existed prior to the commencement of mining operations and mine spoil settlement.     

Dewatering of Multi-aquifer Unconsolidated Rock Opencast Mines: Alternative Solutions with Horizontal Wells

Horizontal directional drilling (HDD) can be a cost-effective way to dewater excavations and surface mines. Laboratory and field experiments provided insight into the important processes involved and allow us to reproduce them through modelling. A new algorithm based on the flow equation by Manning–Strickler was developed and introduced into the groundwater model, PCGEOFIM^®, which allows one to calculate open channel flow within HDD wells. The experimental and numerical results clearly showed that HDD wells have certain advantages over vertical wells, such as more cost effective dewatering in thin aquifers. Additionally, free flowing HDD wells dewatering technology allow mining to proceed without requiring the removal of the wells.     

The Relationship Between Groundwater in the Nováky Coal Deposit and the Thermal Waters from the Bojnice High Block (Slovakia)

Slovakia is very poor in coal reserves but it is extremely rich in mineral and thermal water resources. The Nováky coal deposit is situated near the Bojnice spa, which is among the oldest and most important spas in Slovakia. Due to their proximity, there is a risk that coal mining could adversely affect the Bojnice thermal water resources. We evaluated the results from several surveys as well as groundwater monitoring (inflows to the mining area, overflows from surface wells, and groundwater levels relative to the aquifer systems) and groundwater chemical processes near the Nováky coal deposit and explained the relationship between the groundwater in the Nováky coal deposit and tectonically uplifted Bojnice High Block.

     

侏罗纪煤田宝塔山砂岩含水层大流量大降深放水试验

为了在抽水试验的基础上进一步查明侏罗纪煤田宝塔山砂岩含水层的水文地质特征,开展了井下放水试验,单孔放水量平均值为237.91 m3/h,多孔放水量平均值为444.10 m3/h,宝塔山砂岩含水层地下水位下降最大值达310 m.通过大流量大降深放水试验,计算出含水层的渗透系数和单位涌水量,确定宝塔山砂岩含水层与白垩系、煤...     

某酸法地浸铀矿山全采区地下水流场变化数值模拟

区域流场是地下水中溶质迁移的基础,其形态特征是判断地浸铀矿山地下水环境影响范围的前提,准确预测区域流场的变化情况对指导地浸铀矿山生产实践有着极其重要的作用。本文以我国北方某地浸铀矿山为研究对象,利用数值模拟方法再现了该地浸铀矿山生产以来全采区地下水流场变化情况。模拟结果表明,生产井的抽注活动是区域地下水流场变化的根本原因,采区内部由于生产井的抽注活动,注液井周围会形成小范围的水头升高区,形成点源,抽液井周围则形成水头下降区,成为点汇;但生产期间总抽液量大于总注液量,全采区整体上形成了明显的水头下降区,区域降落漏斗的形成可以有效控制浸出液中溶解组分的迁移范围。结合含矿含水层地下水pH、铀、硫酸根背景值及采区监测井监测数据,进一步证实了区域流场形态对地下水中溶解组分迁移范围的控制作用,得出该地浸铀矿山的地下水环境影响控制在了150 m以内。     

某地浸铀矿山铀煤共采开发研究

内蒙古地区赋存大量的铀煤共生矿床,以某煤矿和铀矿床为典型,煤矿开采地下水位要求低于1060m,而铀矿开采需要地下水位在1340m以上。为解决这一矛盾,运用三维数值模拟技术,对矿区地下水进行了模拟,并首次运用水力帷幕,确定了水力帷幕的主要参数。运用数值模型对该方案进行了验证,证明运用水力帷幕可以保证水位维持在1340m。解决铀煤共采的难题,为内蒙古地区以及其他地区的铀煤共生矿床开发提供了解决方案。