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1.
Coalfields in North China encompassing more than ten Provinces contain six to seven coal seams in the Permo-Carboniferous strata. The lower three seams, accounting for 37% of the total reserves, are threatened with karst water from the underlain Ordovician limestone. Hundreds of water inrush incidences have occurred in which a large amount of water suddenly flows into tunnels or working faces under high potentiometric pressure and over 30 mines have been flooded over the last 20 years. Large-scale dewatering or depressurizing of the karst aquifer was considered essential to avoid water inrushes and keep the mines safely operational. This practice has caused sinkholes, dry springs, water supply shortage, and groundwater contamination in the surrounding areas, which is environmentally not permitted. One of the alternative water control measures is to make full use of the rock layer between the coal seam and the karst aquifer as a geological barrier. Similar to the application in the nuclear industry where a geological barrier is used to contain radioactive wastes, the barrier of this application is considered a hydraulic barrier as well with the objective to prevent or constrain water flow from the underlying aquifer into mines. Its effectiveness to constrain water flow is described by a parameter referred to as hydrofracturing pressure (Phf). When the water pressure in the underlying aquifer exceeds Phf, a wedging effect takes place within the fractures of the geological barrier and, as a result, water inrush occurs. In-situ hydrofracturing tests were used to determine Phf in bauxite and silty sandstone at tunnels. The Phf in the silty sandstone is larger than that in the bauxite but they both vary with depth (distance from the bottom of the tunnel). Based on the test results, a new safety criterion for water inrush was derived for mines and it has been successfully applied to mining practices with the minimum effort of dewatering in the karst aquifer. The same criterion can also be applied to tunneling and quarrying in areas with similar geological conditions. 相似文献
2.
Coalfields in North China contain six to seven coal seams in the Permo-Carboniferous strata. The coal seams are underlain by the Ordovician limestone. Large-scale dewatering or depressurizing of the karst aquifer was considered essential to avoid water inrushes and keep the mines safely operational. This practice, however, has caused water supply shortage in the mining areas. The most effective solution to this conflict is to use the uncontaminated karst water from the mines for water supply. This paper explores a management model to maximize the utilization of the karst water while maintaining the safe operation of the mines. The model can provide essential information on water resource distribution for decision makers. The model was applied to the Dongshan Coal Mine in Taiyuan City, China. 相似文献
3.
华北型煤田煤层开采对含水层的破坏模式研究 总被引：2，自引：0，他引：2
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。 相似文献
4.
注浆改造是华北型煤田下组煤开采的有效防治水技术之一。但是目前该项技术只能解决浅部上组煤问题,随着采深的增大,注浆改造煤层底板薄层灰岩含水层已不能满足安全开采条件。以东庞矿下组9号煤开采为例,分析了奥陶纪峰峰组岩溶含水层富水特征,研究了对奥陶系顶部进行注浆改造的可行性和相关技术问题,得出,对东庞矿奥灰上部进行注浆改造在技术上是可行的,合理的注浆改造厚度为40 m。试验性注浆结果表明,钻孔涌水平均堵水率达到74%,注浆效果良好,并提出了下一步防治水工作建议。 相似文献
5.
Z. Wanfang 《Environmental Geology》1997,30(3-4):280-284
The Hanxing mining area of North China includes three coalfields: Fengfeng, Handan and Xingtai. Six or seven coal seams can
be commercially mined in Permo-Carboniferous strata, among which the lower three, accounting for 37% of the total reserves,
are threatened with karst water from the underlain Ordovician limestone. Hundreds of water inrush accidents have occurred
and over 30 mines have been flooded, resulting in heavy economic losses and casualties. In order to avoid water inrushes and
keep the mines safely operational, dewatering in the karst aquifer was considered an essential measure. Unfortunately, this
practice has caused serious environmental problems such as surface subsidence (sinkhole), dry spring, and water supply shortage.
On the basis of a series of investigations and tests in the last 20 years, an alternative method, mining with water pressure,
has been proposed and is the main focus of this paper. By using this method, the karst water in the limestone can be preserved
to some extent and the coals can be mined in a relatively safe way.
Received: 22 March 1996 · Accepted: 8 April 1996 相似文献
6.
经坊煤矿目前开采的山西组3号煤层逐步枯竭,矿井设计开采太原组8、9、14、15号煤层。奥陶系峰峰组是太原组煤层底板的间接充水含水层。以往大多数勘查成果得出该地区峰峰组岩溶裂隙发育较差,富水性弱-中等的结论,以至于个别矿井在奥灰带压开采危险性评价时甚至将其视为相对隔水层。因此,查明峰峰组的水文地质特征是太原组煤层能否实现安全带压开采的关键。通过岩心采取、抽水试验和水化学分析等多种手段的勘查认为:该地区峰峰组富水性普遍较强,处于主径流带附近富水性极强。该研究对于长治南部地区供水勘查和太原组煤层安全带压开采具有重要的指导意义。 相似文献
7.
The mining depth of main coal mines could reach around 600 m in eastern North China, and extends to the dept with speed of around 12 m/a. As the basement of eastern North China-type coal mine, the Ordovician karst aquifer is the main water source that influences the carboniferous coal seam mining. As the deep karst water has large buried depth and high water pressure (8–12 MPa), with10–30 m space between high pressure aquifer and coal seam, the geological area of deep coal occurrence is often forbidden for mining. Environmental damage, to a greater or lesser degree, is caused by coal mining. On the basis of analyzing the hydrogeological conditions of mining areas, this paper introduces the hydrogeological survey work of ultra-high confined karst water deep in the coal seam floor within researched region for preventing and controlling water disaster of the mine. After researching into the hydrogeological investigation data in the researched region, we explored the hydrodynamic and water chemical characteristics of deep karst water by using pumping test, dynamic observation, and dewatering test. Finally, this study suggests that the hydraulic pressure of deep mining could be mined, on the circumstances that reasonable and effective of water prevention measures are taken based on a detailed survey on water abundance of deep karst. 相似文献
8.
高阳煤矿主采太原组9-10-11#煤层,矿区内断层、陷落柱发育,奥陶系灰岩溶裂隙水是威胁矿井安全开采的主要水源。据井下突水资料及地面水文地质勘探成果,总结出奥陶系峰峰组岩溶裂隙含水层的赋存特征:①从垂向上看,一段以泥灰岩、石膏、硬石膏为主,为相对隔水层,二段由青灰色及黑色厚层状泥晶、粉晶灰岩组成,钻探可见岩溶裂隙,富水性中等;②从水平方向上看,西部埋藏较浅区富水性明显强于中、东部深埋区,且在向斜轴部出现滞流区;③水位西高东低,相差近300m;④顶部存在隔水层段,隔水层厚度一般3.09~34.01m;⑤水位和水化学特征对比发现,峰峰组与马家沟组含水层没有水力联系;⑥地下水总体自西向东,自北向南径流,侧向径流排出井田外。该研究为煤矿底板水的防治提供了依据。 相似文献
9.
The karst paleo-sinkhole is a special geological structure widely found in the coal measures of northern China. Some paleo-sinkholes
have high permeability and connectivity, making them excellent connectors between the karst aquifer and the coal seam. Consequently,
during coal extraction disastrous water inrushes take place frequently, which cause severe loss not only in mine submersions
and personnel casualties, but also in environmental quality. Locations and the geological and hydrogeological characteristics
of paleo-sinkholes in northern China are presented. In-situ drilling and excavation results show that paleo-sinkholes have
different hydrogeological behaviors in different regions and in different mines. Based on observed data, mining-induced strata
failure in the seam floor is analyzed. The existence of paleo-sinkholes increases the floor strata failure zone. Numerical
simulation then is adopted to model coal mining with the effects of both the paleo-sinkholes and the water pressure in the
confined aquifer. Analyses of the simulation conclude that the paleo-sinkhole induces the increase in the strata failure and
deformation. These make water inrushes more likely to happen. 相似文献
10.
Being the basement of coal measure strata in North China coal mine, the Ordovician karst aquifer is the baleful source of water for exploiting the Carboniferous coal bed. The coal mines that the exploitation transfers into the deep stratum will be threatened by deep high or super-high pressure confined water from Ordovician. Mastering the vertical development law is one of the basal and prerequisite works for emancipating deep coal resources and ensuring safety for exploiting the deep coal bed. Based on the statistics of exploratory boring data, a slide test and an X-ray diffraction experiment, the results of Ordovician vertical development were obtained. The results are as follows: limestone karsts 0–30 m below the top are undeveloped; those 30–50 m away from the top are the most developed, and those over 50 m are also undeveloped similar to the first ones. The property of the aquifer of the Ordovician limestone karsts from the working face floor (numbered as 101002) in the Caozhuang coal mine is explored using a 3D high-density electrical technique for the well and drill hole data. This confirms the vertical development law and provides evidence for floor prevention and control of water disasters. 相似文献
11.
新集二矿的主采煤层位于山西组的底部,受到下伏太原组岩溶裂隙含水层的威胁。为缓解井下的防治水压力．采用了在地面施工排水孔的防治水思路。根据钻孔的位置及地层情况,采用了泥浆循环钻进与空气潜孔锤钻进相结合的方法。由于在钻孔施工过程中,发生了泥浆向巷道渗漏的情况,为保证钻孔施工安全及井下生产安全而对钻孔设计深度进行了调整,从而顺利的完成了该孔的钻探施工任务。此孔的成功,可为类似地区施工矿井防治水钻探工程提供借鉴。 相似文献
12.
在详细论述山西省各时代代煤层、含水层与隔水层的相互组合关系,山西省六大煤田与煤田开采有关的上覆与下伏各含水层的发育特征及水动力特征的基础上,指出目前山西省煤矿水害防治的重点是煤层下伏中奥陶统岩溶裂隙水、老空水及老窑水。 相似文献
13.
Hao Li Haibo Bai Jianjun Wu Changshen Wang Zhanguo Ma Yabo Du Kai Ma 《Arabian Journal of Geosciences》2017,10(21):468
Water inrush into coal mines from aquifers underlying coal seams often causes serious casualties and economic losses. The key to preventing the disaster is to discover a water inrush mechanism suitable for specific geological and hydrogeological conditions and apply reasonable control measures. A case of the Chensilou mine is studied in this paper. Complex geological and hydrogeological conditions, such as 12 aquifers in the floor and small distance between coal seam and aquifer, make the mining face in the synclinal basin have a great risk of water inrush. In addition, as an important way to prevent the disaster, grouting will aggravate the risk of water inrush from the floor. The slurry will drive groundwater in the limestone aquifers L8, even L7 and L6 along the horizontal (fracture zone in L11~L8) and vertical (Fs1 ~Fd1) water flow channel into the mining face and synclinal basin. A new water inrush mechanism driven by grouting is formed. In order to prevent this disaster, based on statistical law of hole deviation, the relative error of vertical depth and the angle between the borehole and the rock formation are obtained. Finally, an improved grouting method is proposed, which is useful to ensure the safe production of coal mine and reduce the cost of grouting. 相似文献
14.
煤炭开采后峰峰矿区奥陶系岩溶水硫酸盐演化过程研究 总被引：5，自引：3，他引：2
文章运用水化学和同位素水文学等手段,寻求奥陶系岩溶水硫酸盐演化过程的“指纹”,通过不同含水层间水化学、稳定同位素差异的比对,分析其与上覆含水层间的水力联系和硫动力分馏过程,阐述采矿活动影响下峰峰矿区奥陶系岩溶水硫酸盐的演化过程。研究结果表明:煤矿开采后,峰峰矿区奥陶系岩溶水硫酸盐含量普遍增高,演化特征呈现多样性,存在多种硫动力分馏过程。分馏动力主要来自矿坑水和孔隙水通过导水裂隙的渗漏（越流）补给,以及脱白云石化过程中自身蒸发岩矿物（石膏）的溶解。 相似文献
15.
鄂尔多斯盆地北部深埋煤田区地表主要有沙漠、基岩台地和黄土沟壑等地貌类型,沙漠区工作面涌水量比其他地貌区大1~2个数量级。为了查清煤层顶板直接充水含水层补给水源、导水通道和充水强度的控制要素,从地形地貌和地质沉积方面开展了研究,结果表明:沙漠地貌地势平缓,降水入渗系数大,第四系厚度大、富水性强,为下伏含水层提供了丰富的补给水源;基岩台地和黄土沟壑地貌,地形起伏大,降水入渗系数极小,浅部地层富水性极弱,是下伏含水层补给能力较弱的水源。陆相沉积形成的砂泥岩互层结构,不存在区域性稳定隔水层,各层段均属于弱-中等富水性含水层,3个矿井的白垩系含水层水位下降了20~130 m,证明浅部与深部含水层存在较密切的水力联系。煤层顶板主要发育七里镇砂岩和真武洞砂岩含水层,为厚度较大的中粗砂岩段,直接充水含水层地质沉积条件相似,但是沙漠区工作面顶板钻孔水量、累计预疏放水量和采空区涌水量均远大于其他地貌区,直接充水含水层富水性主要受地貌控制,深部含水层的水源为大气降水和第四系含水层。沙漠地貌区的不同矿井,工作面顶板钻孔水量、累计预疏放水量、采空区涌水量也存在较大差异,该差异与直接充水含水层厚度和岩性等有关,反映了地质沉积条件也是控制含水层富水性的重要因素。地形地貌和地质沉积是控制直接充水含水层富水性和工作面涌水量的关键要素。 相似文献
16.
鄂尔多斯盆地周边分布着神东、陕北、黄陇和宁东四个大型煤炭基地,煤炭资源丰富,但开采利用程度低,是我国＂十二五＂期间重点开发的矿区。在系统分析盆地内侏罗系煤层顶板白垩系裂隙含水层和第四系萨拉乌苏组孔隙含水层富水性的基础上,揭示了含水层与煤层的叠置关系;以煤炭开采破坏含水层、煤层与含水层距离、煤层与地表距离、含水层富水性为依据,将含水层破坏模式划分为：破坏顶板萨拉乌苏组含水层亚区、煤层埋藏浅破坏顶板含水层及生态环境亚区、破坏顶板含水层富水性较好亚区、破坏顶板含水层富水性较弱亚区,并对含水层破坏程度进行了分区评价;最后提出了含水层保护措施,为煤炭开采后的防治水工作提供了依据。 相似文献
17.
Dan Huang Zaibin Liu Wenke Wang Shenghui Nan Li Chen Yaoquan Gao 《Environmental Earth Sciences》2018,77(22):761
Water inrush from Ordovician karst aquifer in North China coal mine has become a key issue on underground coal mining. To address this problem, it is necessary to identify fault zones, because fault zones might connect limestone aquifers and coal seams, enabling Ordovician karst water to enter the mine. In the study area, a series of parallel directional holes were drilled along Ordovician limestone at depths between 70 and 90 m under Ordovician limestone boundary. To conveniently detect fault zones and govern mine water disasters, a series of natural gamma-ray logging while drilling (GRLWD) were undertaken. The entire detecting region can be comprehensively covered by several directional borehole groups. Then, fast Fourier transform and short-time Fourier transform approaches were employed on the basis of GRLWD data and geological data to extract faults information. A segmented identification method for deep fault zones was established in this study. This method can be used to markedly improve the identification of fault zones within Ordovician limestone or the unitary lithology formation and provide crucial information relevant for deep coal mining safety. 相似文献
18.
煤炭开采条件下三姑泉域岩溶含水层保护评价 总被引：1，自引：1，他引：0
三姑泉域是我国典型的北方岩溶区,同时位于国家规划的晋东大型煤炭基地,煤炭开采与水资源保护之间的问题较为突出。多年来区内煤炭资源的大规模开采造成了区域地下水位下降、水质恶化等现象。因此开展北方岩溶区煤炭基地含水层保护评价对水资源保护及经济可持续发展具有十分重要的意义。本文从含水层脆弱性、含水层功能和煤炭开采影响力三方面建立综合评价指标体系,采用APH法进行三姑泉域岩溶含水层综合保护评价。针对煤炭基地特征,采用增加了煤炭采空区指标的COP修正模型评价了含水层的脆弱性。含水层功能评价分别从供水能力与生态、大泉维持能力开展;煤炭开采影响力评价从开采活动及煤炭地质结构两方面开展。综合评价结果显示需要重点保护的区段为岩溶大泉、水源地及地表渗漏段,其次为岩溶强径流带及煤炭剧烈开采区,与实际情况相符。 相似文献
19.
Wenping Mu Qiang Wu Yuan Xing Cheng Qian Yang Wang Yuanze Du 《Environmental Earth Sciences》2018,77(5):215
Water inrush from a karst aquifer threatens mine safety in North China because of the special hydrogeological conditions. This paper systematically analyzes the regional hydrogeological conditions of the Cambrian–Ordovician limestone karst aquifer in the Yuxian Basin. Conceptual and mathematical models of karst water flow system are established, and the karst water flow system is simulated by the finite-difference method. The numerical model is checked using hydraulic head from karst water observation holes, and the sensitivity of hydrogeological parameters is analyzed. Further, the risk of water inrush from the karst aquifer underlying the coal seam in the second mining area of the Beiyangzhuang Mine in the basin is evaluated by the water inrush coefficient method. Based on the critical hydraulic head for mining safety, the rate of mine dewatering is simulated for the three stages of the mining plan with the numerical model. The results show that the risk of water inrush in the second mining area is high. The rate of dewatering in the three stages without grouting is 1300, 1860, and 2050 m3/h, respectively, and with local grouting is 1020, 1550, and 1700 m3/h, respectively. Dewatering combined with grouting not only ensures coal mine safety, but also significantly reduces the rate of dewatering. The prediction method of mine dewatering has practical significance in engineering applications. 相似文献
20.
There were three landforms (i.e. desert, bedrock platform and loess gully) in deep-buried coalfield of northern Ordos Basin. Water inflow of working face in desert area was 1~2 orders of magnitude larger than that in other landform areas. In order to find out the key controlling factors of the directly water filled aquifers on the roof of the coal seam, we carried out research from the aspects of topography, landform and geological sedimentation. The results showed that desert landform provides abundant recharge water for underlying aquifers because of gentle topography, large precipitation infiltration coefficient, thick and water-rich quaternary system. While bedrock platform and loess gully landform were the water sources with weak recharge capacity of underlying aquifers. The sandstone-mudstone interbedding structure formed by continental deposits resulted in the absence of regional stable aquifers in Jurassic and Cretaceous strata on the roof of coal seams. Pumping tests of boreholes showed that all strata belong to weak to medium water-rich aquifers. The groundwater level of Cretaceous aquifer decreased by 20~130 m in three mines. There was a close hydraulic relationship between shallow and deep aquifers. The Mesozoic strata belonged to fluvial deposits. Qilizhen sandstone and Zhenwudong sandstone aquifers were mainly developed on the roof of the coal seam, which were characterized by thick medium-coarse sandstone sections. The geological and sedimentary conditions of direct water-filled aquifer were similar, but the amount of borehole water, cumulative pre-drainage water and water inflow from goaf in desert geomorphic area were much larger than those in bedrock platform and loess gully geomorphic area. The water-rich of the aquifer was mainly controlled by geomorphology, and the water sources of the deep aquifers were meteoric precipitation and Quaternary aquifer. In different mines with similar Quaternary conditions in Mu Us Desert, there were also great differences in the amount of borehole water, cumulative pre-drainage water and water inflow from goafs. The difference was related to the thickness and lithology of the aquifers. It reflected that the geological sedimentary conditions of the coal seam roof were also important factors to control the water-rich of the aquifers. Topography, landform and geological sedimentation were the key factors to control the water-rich of the aquifer directly and the water inflow from the working face. 相似文献