华北型煤田煤层开采对含水层的破坏模式研究

华北地区岩溶水系统分布广泛、水质好、水量丰富,是城镇工矿企业的重要水源,也是维护生态稳定的重要因素。华北型煤田大部分位于岩溶水系统之中,煤炭开采时水患与缺水并存,煤水矛盾突出。在总结了华北型煤田中煤炭基地的煤层及含水层发育情况的基础上,根据岩溶水系统的补径排条件、煤层分布区与岩溶水补给区的位置关系、地形地貌等因素,将采煤对岩溶含水层破坏类型分为三种类型:直接破坏、间接破坏型和无影响型;按地下水类型划分;将煤层开采对含水层的破坏模式划分为破坏顶板孔隙水、破坏底板岩溶水及破坏岩溶水、裂隙水、孔隙水3类,近而根据含水层性质及埋藏条件,含水层与煤层的位置关系,对煤矿开采对区域含水层破坏的模式划分了亚类。在进行含水层破坏类型和破坏模式划分的同时,也对各类型的特征进行较为详细的说明,为该区的煤炭开采和水资源的保护指明了方向。     

某煤矿开采中含水层的破坏及其防治措施

在分析煤矿开发方案及其地质环境的基础上,从含水层的结构、水位和水质三个方面研究煤矿开采对含水层的破坏,并提出留设防水煤柱、污水处理和含水层监测的含水层防治措施,以保护地下水资源.     

矿山开发中的含水层破坏评估方法初探——以白山市恒基煤矿为例

本文以白山市恒基煤矿为例,在阐述矿区地质环境基础上,探讨了矿山开采中的含水层结构破坏评估方法,含水层水位、水量变化、和采矿活动对含水层水质造成的污染。最后提出了防治措施,为矿山地质环境恢复治理提供科学依据,也为其他矿山开采提供参考。     

永夏煤田顺和煤矿水文地质特征分析

本文结合区域水文地质条件,对矿井主要含水层和隔水层进行了分析和评价。对矿井主采二2煤层充水因素进行了分析,尤其是断层构造。指出山西组煤层顶板砂岩裂隙水为二2煤层充水的重要因素之一,导水断裂构造、封闭不良钻孔等可能导通石炭系太原组灰岩岩溶裂隙含水层和奥陶系灰岩岩溶裂隙含水层,可造成突水淹井事故。     

采煤对含水层破坏模数的计算--以太原西峪煤矿为例

通过 对 采 煤 排 水 量 与 降 水 量 历 时 曲 线 的 分 析 ,以 及 其 相 对 应 的 开 采 面 积 ,求 得 采 煤 对 井 田 含 水 层 的 破 坏 模数 ,并 以此 求 出井 田内 的 含水 层资 源 量,为 正 确评 价采 煤 对含 水层 的 破坏 程度 提 供依 据。     

矿山生态环境破坏及修复方法分析——以峨眉山市为例

矿山开采活动在获得经济利益的同时,势必给原有的生态环境带来严重破坏和影响。以峨眉山市矿山情况为例,分析了矿山开采引起的矿山地质灾害、含水层破坏、水土环境污染、地形地貌景观破坏等生态环境破坏类型,同时,以峨眉山市8个矿山为例,探讨分析了矿山生态环境修复方法。     

煤矿区水资源论证探讨——以富源县丹烁煤矿为例

煤矿开采对水资源的影响十分复杂，可使含水层结构和构造破坏，引起地下水补、径、排关系变化，加上煤矿疏排水的延续、水-岩作用以及所处化学环境的改变，。引起地下水质和量的变化。同时，地表水与地下水、矿坑排水发生直接的水力联系，破坏了正常的水环境，并引起泉水干涸、地表塌陷、井筒破坏、土地荒漠化等灾害。因此，煤矿区的水资源保护问题理应引起高度重视。     

灰岩含水层中稀土元素在地下水与围岩间的分异:以皖北任楼煤矿太原组灰岩含水层为例

采取了皖北任楼煤矿太原组灰岩和灰岩水样品进行稀土元素测试分析,结果显示灰岩样品稀土总量较低,平均为36.947×10-6,灰岩样品稀土配分模式表现为轻稀土富集、重稀土亏损型;灰岩水样品稀土总量平均为0.052 6×10-6,灰岩水样品轻、重稀土均富集,轻、重稀土之间分异明显。对灰岩含水层水岩相互作用进行研究,结果表明:轻稀土表现稳定,重稀土分异明显,尤其在Y处有一个明显的峰值;Y元素与Ca元素呈正相关关系,相比石灰岩,灰岩水的Y/Ho、Y/Dy分异更为明显。研究认为,灰岩水中Y元素的峰值效应也可作为灰岩水源识别的依据。     

百善煤矿含水层下留设防砂煤柱开采的地质保障系统

通过对百善煤矿十几年来中等富水性的松散含水层下留设防砂煤柱开采的实践,总结出一套确保成功开采的地质保障系统,并对该系统的各个组成部分进行定性、定量分析。指出地质保障系统是矿井优化设计、实现安全高效的前提条件和基础保证,具有巨大的决策效益和经济效益。     

淄博煤田洪山、寨里闭坑矿山地下水串层污染预测与防治措施研究

淄博煤田洪山、寨里煤矿区内存在大量无止水措施、止水措施不良以及止水遭受破坏的供水井,这些井孔使矿坑水与奥灰水形成水力联系。矿山闭坑后,老窑积水和井巷水大量串层进入奥灰水含水层,影响了地下水化学场和动力场,改变了地下水系统的原有状态,使奥灰水水质逐年恶化,严重威胁了工农业供水安全。通过创建研究区水文地质概念模型及结构模型,运用Visual MODFLOW软件进行数值计算,并采用1989-2002年历史序列资料和2003-2012年实测资料分别对模型进行识别与验证,对现状条件和实施封孔治理措施后研究区奥灰水水质的动态变化进行预测,结果表明：(1)受矿区串层影响,矿坑老窖水随水流进入串层通道,对奥灰水造成污染,典型污染物是SO₄^2-离子,在不采取应对措施的前提下,以2013年污染物浓度场作为模型初始浓度条件,对研究区进行10、20、25、30 a模拟预测可知,2020年之前SO₄^2-浓度增加幅度较大,随后水位差逐渐变小,串层补给作用减小,后期浓度增幅逐渐变缓,2038年以后,奥灰水浓度升高趋势减缓,但水质...     

山西省煤炭开采对上覆裂隙水破坏及其利用的研究

针对山西省煤炭资源的大量开采,含水层遭到破坏并改变了储存状态的现状,采用动储量破坏及静储量破坏评价方法来计算被破坏的水资源量。通过确定开采面积、岩石含水系数及采煤破坏地下水模数等参数,计算求得山西省自煤炭开采以来破坏的地下水静储量71 388万m^3,地下水动储量71 370m^3/h,为合理利用山西省水资源提出了合理化建议及相应措施。     

淄博市洪山、寨里煤矿地下水串层污染形成原因及防治

淄博市洪山、寨里煤矿区隐伏的奥陶系灰岩裂隙岩溶水污染严重。水质污染突发于矿坑全面闭坑以后，污染范围与矿坑水区一致，地下水污染组份与矿坑水的高含量组份相同。水质恶化主要由矿坑水串层污染所致。在此针对串层污染形成原因及影响因素，提出了防治对策。     

典型矿区深层地下水重金属含量特征及健康风险评价——以皖北矿区为例

以皖北矿区为例,分析测试了不同含水层(松散、煤系、太灰、奥灰)中的6种重金属元素(Cd、Cr、Cu、Zn、Pb、Ni),对其含量特征及健康风险评价进行了研究。结果表明,6种重金属在不同含水层含量大小次序各不一样,从整体来看,研究区地下水中所测重金属含量依次为NiZnPbCuCdCr,与太灰水一致;整体地下水中Cr、Cu和Zn均未超过(GB/T14848—93)中Ⅲ类水质标准,Cd、Pb和Ni有部分水样超过标准限值。化学致癌物Cd和Cr在各含水层所致健康危害风险值数量级在10-6~10-4 a-1,Cr健康风险值在各含水层中均大于Cd,Cr在煤系含水层危害风险值(1.29×10-4 a-1)已超过美国环境保护局(USEPA)最大可接受风险(1×10-4 a-1),为研究区首要的环境健康风险管理控制指标。化学非致癌物Cu、Zn、Pb、Ni四种重金属健康危害风险值较小,数量级在10–11~10-8 a-1,Pb和Ni健康危害风险值相对较高,也应引起重视。各含水层总的健康风险值大小次序为:煤系太灰奥灰松散,前三者已超过国际辐射防护委员会(ICRP)推荐的(5×10-5 a-1)最大可接受风险,其中煤系含水层总的健康风险值为1.46×10-4 a-1,已超过USEPA(1×10-4 a-1)推荐的最大可接受风险。对矿区深层地下水开展重金属含量分析和健康风险评价,可为地下水水资源的开采利用和保护提供参考。     

Effects of Poisonous and Harmful Elements Brought about by Coal Mining on Water Environment in Zibo Coal Mine, Shandong Province, China

INTRODUCTIONZibo lies in the center of Shandong Province,China.Thetopography of Zibo is high in the south and low in the north.Zibo is characterized by hills in the east,the south and thewest,and a wide plain in the north(Fig.1) .The annual rain-fall is 5 0 0 - 70 0 mm .The coal resources are very abundant in Zibo.There areXiazhuang,Xihe and Hongshan coal mines in the researcharea.The m ining sewage,about 0 .844 2× 10 8m3/ a,accountsfor about80 % of runoff of the Xiaofu River.The X…     

Effect of Underground Mine Blast Vibrations on Overlaying Open Pit Slopes: A Case Study for Daye Iron Mine in China

Investigating the propagation and attenuation of blast vibration in rock slopes is the key point to assess the influence of underground mine blasting on overlaying open pit slopes stability and determining the potential risk. In this paper, Daye Iron Mine in China has been chosen as the case to study the effect of blast vibrations on overlaying open pit slopes due to underground mine blast. Firstly, the characteristics of blast loadings are analyzed by the dynamic finite element method. Then, a three dimensional (3D) numerical model of the open pit and the underground mine is made, which is verified by the field monitoring data to prove its reliability. The effect of blast vibration on overlaying open pit slope due to underground mine blasting are discussed based on the peak particle velocity (PPV) and the peak effective tensile stress (PETS) distribution characteristics which are calculated and analyzed by inputting the obtained blast vibration data into the numerical model. The results show that the effect of present mining blasting on the stability of pit slopes are limited because the simulated maximum PPV and PETS of monitoring point on slopes are all < 0.747 cm/s and 0.738 MPa. At last, according to numerical simulations of the underground mine blasting, the PPV predicting formulas for the slopes in Daye Open Pit Iron Mine is proposed based on the classic Sadaovsk formula.     

Reliability Analysis of Rock Supports in Underground Mine Drifts: A Case Study

Geotechnical and Geological Engineering - Support failures in mine drifts represent potential hazards that threaten underground mine safety and productivity. The aim of this study is to determine...     

Coal Mine Roadway Stability in Soft Rock: A Case Study

Roadway instability has always been a major concern in deep underground coal mines where the surrounding rock strata and coal seams are weak and the in situ stresses are high. Under the high overburden and tectonic stresses, roadways could collapse or experience excessive deformation, which not only endangers mining personnel but could also reduce the functionality of the roadway and halt production. This paper describes a case study on the stability of roadways in an underground coal mine in Shanxi Province, China. The mine was using a longwall method to extract coal at a depth of approximately 350 m. Both the coal seam and surrounding rock strata were extremely weak and vulnerable to weathering. Large roadway deformation and severe roadway instabilities had been experienced in the past, hence, an investigation of the roadway failure mechanism and new support designs were needed. This study started with an in situ stress measurement programme to determine the stress orientation and magnitude in the mine. It was found that the major horizontal stress was more than twice the vertical stress in the East–West direction, perpendicular to the gateroads of the longwall panel. The high horizontal stresses and low strength of coal and surrounding rock strata were the main causes of roadway instabilities. Detailed numerical modeling was conducted to evaluate the roadway stability and deformation under different roof support scenarios. Based on the modeling results, a new roadway support design was proposed, which included an optimal cable/bolt arrangement, full length grouting, and high pre-tensioning of bolts and cables. It was expected the new design could reduce the roadway deformation by 50 %. A field experiment using the new support design was carried out by the mine in a 100 m long roadway section. Detailed extensometry and stress monitorings were conducted in the experimental roadway section as well as sections using the old support design. The experimental section produced a much better roadway profile than the previous roadway sections. The monitoring data indicated that the roadway deformation in the experimental section was at least 40–50 % less than the previous sections. This case study demonstrated that through careful investigation and optimal support design, roadway stability in soft rock conditions can be significantly improved.     

Stability Assessment of a Pit Slope Under Blast Loading: A Case Study of Pasir Coal Mine

In Pasir mine, coal seams and host rocks of varying thickness have been uniquely deposited with an average dip angle of 85°. The host rocks are weak and mainly composed of mudstone and sandstone comprising of 90–95% of the total pit volume. The thickness of coal seams and host rocks ranges from sub-metric to few tenths of meter. The overall safe pit slope angle was evaluated to be 27° for mining depth of 50–150 m. Several slopes failure incidents have occurred in the mine causing considerable disruption in production and monetary loss. It is envisaged that slope failures may be triggered due to blasting conducted in steeply dipping stratified deposit. In order to investigate the causes of slope failures, peak particle velocity (PPV) and accelerations at various locations from the blast site have been measured. In addition, finite element models of pit slope have been analyzed by applying static or gravity loading as well as blasting or dynamic loading. This paper elaborates the results of in situ measurements of ground vibration and numerical investigation and suggests possible causes of slope failures in Pasir mine.