湖南宁乡大成桥充水矿山疏干区岩溶系统水气压力监测及突变特征

湖南煤炭坝煤矿是我国著名的大水矿山,开采标高已降至-400 m,每小时排水量11 000 m3。长期的疏干排水,已形成面积达219.19 km2的地下水降落漏斗。以往的调查资料表明,矿山疏干诱发的岩溶塌陷主要发生在疏干开始、地下水位下降到基岩面附近、矿坑发生突水突泥灾害等3个阶段,在疏干区应该无诱发因素导致岩溶塌陷的发生。但近年来煤炭坝煤矿疏干区大成桥的岩溶塌陷特征表明,尽管相关部门采取了一系列处置措施,但岩溶塌陷仍然频繁发生。为了进一步揭示该地区岩溶塌陷发育规律,使处置决策更加科学化,作者所在团队选择大成桥为典型区,通过岩溶系统地下水气压力监测,分析诱发岩溶塌陷的动力来源及其变化规律。结果表明,疏干区岩溶管道裂隙系统中水气压力突变现象极为明显,年最大变幅达54.72 m,瞬时水气压力变化速率最大为70.6 cm/min,造成这一现象的主要原因是气爆、地下洞穴（溶洞、土洞）垮塌。      

The influence of karst features on environmental studies in Turkey

 The carbonate rocks of Turkey, which underlie about one third of the country, possess major water resources with great potential for electricity generation and water supplies. The ongoing development of karst features, especially in the southern part of Turkey, demonstrates specific environmental problems that occur in many karst water supply projects. Karst aquifers, springs, sinkholes, dolines, poljes and other karst features are of great importance from the standpoint of karst water resources and environmental research studies. In karst regions, conservation and protection of groundwater resources for both qualitative and quantitative evaluations is possible only when the catchment area is determined accurately. Since the catchment area in karst terrains is not limited by the surface drainage boundaries and the groundwater flows through well-developed coduits or fissures, the equations used in non-karstic areas cannot be applied to such karstic regions. Studies on the development of karst features and its environmental impacts in Turkey are of recent origin. Therefore, many unreliable methods are being applied in karstic areas. For example, the use of "shallow holes or sinkholes and fault zones" for septic water waste disposal or as sewage by those who are not familiar with karst, sometimes causes very serious problems of extensive groundwater pollution. This paper discusses the development of different karstic features in Turkey and case studies on its environmental impacts. Received: 27 December 1995 · Accepted: 10 July 1996     

湖南郴州地区岩溶塌陷分布规律及其影响因素浅析

通过地质环境调查,分析湖南郴州地区岩溶塌陷分布规律及其影响因素,结果表明:(1)1980-1983年为岩溶塌陷盛发期,平均8.5个?年-1;2012-2020年塌陷发生频率增加,平均5.88个/年;岩溶塌陷主要发生在3-7月份雨季;(2)低丘冲沟中发生塌陷54个,占塌陷总数的55.67％;岩溶平原中发生塌陷40个,占4...     

露天煤矿开采侧向帷幕控水原理与截水效果数值分析

露天煤矿开采过程中的矿坑疏排水是引起地下水资源流失的重要原因,寻求新的控水方法势在必行。以内蒙古赤峰市元宝山露天煤矿为研究对象,根据研究区水文地质与露天煤矿开发特征,分析了露天开采驱动下帷幕墙体建设对地下水系统控制的基本原理,得出帷幕墙体渗透能力越弱、厚度越大、与补给水体距离越近是帷幕墙减少露天采坑涌水的基本思路。将露天采矿疏排水与地下水系统数值仿真研究结合,对露天煤矿开采与帷幕墙建设对矿坑疏排水强度影响程度进行预测分析,模拟结果显示,采用针对主要涌水段的局部帷幕工程方案,地下水仍然以露天矿采坑为降落漏斗中心,区域流场形态基本未发生重大变化,在未帷幕区段地下水发生了强烈的侧向绕流现象,初期(300 d)矿坑残余涌水量较之现有矿坑排水量最大减幅 37.16%,而残余涌水量随时间增大趋势明显。按准全封闭型帷幕方案建墙后,地下水基本未发生绕流现象,矿井残余涌水量为先减小后增大的趋势,最大减幅达85.79%,且后期涌水量增加幅度不大,可见准封闭型帷幕建设方案较之局部帷幕方案对矿坑整体涌水量的减排作用显著。通过分析露天煤矿开采侧向帷幕控水规律,构建帷幕阻水条件下地下水系统仿真模型,评价帷幕截水减排效果,以期为露天矿区煤–水资源协调开发提供科学依据。      

Drainage and flooding in karst terranes

Flooding in karst terranes is a commonly occurring geo-hazard. It causes damage to property, businesses, and roadways. It can lead to the formation of cover-collapse sinkholes and groundwater contamination. Generally, three types of flooding or their combinations are related to karst: recharge-related sinkhole flooding, flow-related flooding, and discharge-related flooding. Understanding of the type of flooding is essential for solving the flooding problem. Areas prone to karst flooding should be recognized, and restrictions and laws on land use should be implemented. Runoff and erosion control plans should address the unique characteristics of karst features. Digging out clogged sinkholes, creating retention basins, or installing Class V Injection Wells are possible solutions to improve drainage of storm water. Solutions to flooding problems in karst areas should also be coordinated with the water quality control to prevent groundwater contamination.     

基于矿井排水的水文地质参数识别

由于强烈的非均质性,如何识别岩溶裂隙含水层水文地质参数是一个由来已久的难题。本文利用焦作矿区、荥巩矿区及永夏矿区生产矿井大流量、长时间的排水资料进行识别岩溶裂隙水含水层的水文地质参数,计算结果发现：K值均在100m/d量级上,μ＊值均在10^-3量级上,与孔隙含水层的值相当;用识别的参数预算矿井涌水量与区域降雨补给量接近,回报水位及给定条件下排水量误差均不超过2%。结果表明,可以用渗流理论模型对管道流、裂隙流进行概化处理。研究成果提出矿区岩溶裂隙地下水参数计算的新方法,为防控矿坑突水、安全生产提供了新思路。     

The influences of coal mining on the large karst springs in North China

Environmental damage, to a greater or lesser degree, is caused by coal mining. On the basis of analyzing the hydrogeological conditions of the mining areas, this paper provides a sum-up of the characteristics of water disasters in North China-type Coalfield. Researching into the Baimai Spring group, this paper explores the relation between karst water and groundwater of coal-measure strata, using the methods of pumping test, dynamic observation, and tracer test. After working over the impact of mine water-inrush on spring dynamics, this paper estimates the contributory level of karst water to mining drainage. This paper holds that the mine water-inrush mainly results from karst water, with the fault structures acting as channels; the keys of mine water-inrush are faulty density, intersection and endpoint fault. Finally, this paper suggests that mining below Mine-9 be forbidden, and that below Mine-7 be properly mined, which provides the scientific basis for preserving springs and preventing water disasters in the mining areas.     

Analysis of water control in an underground mine under strong karst media influence (Vazante mine,Brazil)

This work presents analysis of groundwater flow conditions and groundwater control measures for Vazante underground mine located in the state of Minas Gerais, Brazil. According to field observations, groundwater flow processes in this mine are highly influenced by the presence of karst features located in the near-surface terrain next to Santa Catarina River. The karstic features, such as caves, sinkholes, dolines and conduits, have direct contact with the aquifer and tend to increase water flow into the mine. These effects are more acute in areas under the influence of groundwater-level drawdown by pumping. Numerical analyses of this condition were carried out using the computer program FEFLOW. This program represents karstic features as one-dimensional discrete flow conduits inside a three-dimensional finite element structure representing the geologic medium following a combined discrete-continuum approach for representing the karst system. These features create preferential flow paths between the river and mine; their incorporation into the model is able to more realistically represent the hydrogeological environment of the mine surroundings. In order to mitigate the water-inflow problems, impermeabilization of the river through construction of a reinforced concrete channel was incorporated in the developed hydrogeological model. Different scenarios for channelization lengths for the most critical zones along the river were studied. Obtained results were able to compare effectiveness of different river channelization scenarios. It was also possible to determine whether the use of these impermeabilization measures would be able to reduce, in large part, the elevated costs of pumping inside the mine.     

疏干排水矿区闭坑后岩溶塌陷形成机理探索——以湘中地区恩口煤矿为例

恩口煤矿已关停20年,地下水位已恢复,但地面塌陷灾害时有发生,为了探讨恩口煤矿闭坑后的岩溶塌陷成因机理,总结水位恢复中与恢复后的致塌模型,文章梳理了恩口煤矿区岩溶塌陷的时空分布、土体结构等基本特征,着重于分析煤矿闭矿后岩溶塌陷的发生与地下水位恢复过程的相关性,提出水位恢复中与恢复后2个阶段发生岩溶塌陷的成因机理与致塌模式。第1阶段,主要致塌模式为浮托—软化型,理论模型来源于基坑突涌的产生条件公式,发育地段主要集中在以往塌陷密集分布区,与采矿降水过程中加速土洞的形成相关,塌陷发生的数量明显低于疏干排水过程;第2阶段,致塌模式为潜蚀—失稳型,是指由地下水位在岩土界面自然波动引发的岩溶塌陷,仅零星发生。文章为娄底市进行地质灾害易发性、危险性评价与防治规划,提出科学、经济、可行的防治措施与建议,同时,为湘中类似地区的岩溶塌陷预测与防治区划提供参考。      

重新集铁矿矿坑涌水量预测研究

针对重新集铁矿水文地质条件深入研究,对其进行相应概化,利用解析法以及数值法(分不同开采方案)进行矿坑涌水量预测,得出结论:解析法在矿坑涌水量中局限较大,在矿坑预测过程中更为推荐使用数值法,其预测结果与实际结果更为符合。从具体预测结果来看,最大矿坑涌水量均出现在首采阶段,而在全开采期矿坑涌水量总体变化不大。选择优先开采-160 m水平矿体和-300 m水平矿体两种不同的开采方案时,方案二的最大涌水量较小,有益于井下最大排水规模的控制,同时发现涌水量变幅也相对较平稳,有益于矿山水资源综合利用方案制定和矿山水环境治理方案的设计,建议矿床开采方案选择方案二。     

Natural and human-induced dissolution and subsidence processes in the salt outcrop of the Cardona Diapir (NE Spain)

The Cardona Diapir in NE Spain, with a salt outcrop about 0.9 km² in area, has a well-developed endokarstic system that used to discharge into the Cardener River. Underground mining for potassium salt carried out from 1930 to 1990 caused significant changes in the topography and hydrology of the diapir. The accumulation of two halite slag heaps, totalling around 10 million tons, locally dammed the surface drainage, creating closed depressions and preferential zones of water recharge. The waters that infiltrated in one of these depressions, largely derived from uncontrolled sewage disposal, led to the generation of a 335-m-long human-induced cave excavated in one of the slag heaps. Moreover, the inflow of freshwater from the surrounding sandstone aquifer, caused by the excavation of a ventilation gallery, resulted in the generation of a 280-m-long cave. In March 1998, the interception of a phreatic conduit by a halite mine gallery 50 m deep caused dramatic changes in the hydrology and geomorphology of the diapir, including: (a) a sudden decline in the piezometric level of the karstic aquifer; (b) the inflow of freshwater and debris from the Cardener River into the endokarstic system and the mine galleries. A tunnel had to be constructed to divert the river flow from the salt outcrop; (c) massive dissolution of salt, creating new cavities and enlarging the pre-existing ones, including both mine galleries or cave passages. The 4,300-m-long Salt Meanders Cave was largely generated by the inrush of water from the Cardener River into the mine galleries; and (d) the generation of a large number of sinkholes in the vicinity of the Cardener River. An inventory of 178 sinkholes has allowed us to estimate minimum probability values of 4.7 and 8 sinkholes/km²·year for time intervals previous and subsequent to the 1998 mine flood event, respectively.     

湖南省涟源市岩溶地面塌陷特征分析

涟源市属中低山-丘陵地形,区内碳酸盐岩分布面积广,岩溶发育。由于受采煤活动影响,诱发地面岩溶塌陷48处,造成重大经济损失。岩溶塌陷多分布于岩溶采煤区,发生原因主要是矿坑突水、抽排地下水,使地下水位大幅变动,上覆岩土体失去浮托而产生塌陷。     

滇东南高原岩溶盆地区普阳煤矿的深层涌水趋势分析

普阳煤矿位于一断陷盆地的浅部新近系地层中,矿区被3种类型的水文地质边界圈闭.煤层分布标高低于暗河出口100～230 m,煤田四周及盆地基底均为岩溶含水层,其承压水头高于煤层底板67～268 m,预计最低开采标高的平均承压水头约206 m.为解决矿区地下水突水威胁,监测普阳河水流入和流出的水量,根据水均衡原理及矿坑充水要...     

基于表层岩溶带调控的峰丛洼地低影响开发构建

岩溶峰丛洼地地区石漠化、饮水困难和水污染等环境问题高发,生态环境十分脆弱。低影响开发概念的引入有助于规范开发行为,促进水资源的高效利用,降低石漠化和地下河污染风险。根据水文条件和开发方式岩溶洼地空间分为坡耕地水土流失敏感区、表层岩溶泉水源地敏感区和落水洞污染输入敏感区。低影响开发模式总体是在3类敏感区实现5个管理目标。坡耕地敏感区的低影响开发目标设置为降低农田耗水量和减少水土流失,开发途径是减少蒸发和调控坡面洪水径流。表层岩溶泉敏感区的管理目标是降雨－径流资源化利用和饮用水安全保障,通过实施雨水收集回用工程和设置水源地保护区来实现。落水洞敏感区需要通过设置径流缓冲区和沉淀过滤池来预防污染物进入。我国南方石漠化地区探索和总结出以表层岩溶带降雨－径流管理为特征的低影响开发模式。该模式要求峰丛顶部留置生态保护区涵养水源。岩溶洼地底部为落水洞排洪预留缓冲区,利用岩溶裂缝设置下凹式绿地,实现自然渗透和净化。“峰”、“洼”之间过渡区划定水源地保护区边界,同时设法增加雨水资源化利用率,补充生态和生活缺水量。低影响开发模式也适用于峰丛洼地发育的东南亚和中美洲等地区。      

Mechanism of sinkhole formation during groundwater-level recovery in karst mining area,Dachengqiao, Hunan province,China

The Meitanba Coal Mine area in Hunan province, China, had been impacted by severe cover collapse sinkholes since 1982 due to mine dewatering. After the coal mine was closed in February 2015, the groundwater level has increased significantly. A series of sinkholes were recorded in the study area during groundwater-level recovery. Analysis of monitoring results and in-situ investigation indicated that 13 sinkhole collapses were more likely induced by abrupt change of groundwater–air pressure in response to heavy rainfall from March 2015 to July 2016 when the groundwater level increased by as much as 76 m. When the karst conduit was flooded, a relatively sealed environment was formed between saturated sediments and flooded karst conduit. Implosion of entrapped air might have caused the cave roof to collapse followed by surface collapses in a short time. On the other hand, four sinkholes occurred in November 2016 when the groundwater levels were near the soil–bedrock interface at elevations between 52.5 and 58.9 m amsl and the groundwater-level increase was at slower paces. Field measurements indicate that the groundwater-level fluctuation at the soil–bedrock interface could enlarge the soil cavity and accelerate the subsoil erosion process.     

徐州矿区奥灰岩溶水突出的原因与防治

徐州矿区开采深度大,水文地质条件复杂,水害严重。主要突出水源为奥陶系含水层。突水原因主要有:底板隐伏陷落柱或断层导水;底(顶)板含水层与奥灰含水层对接;顶板冒落裂隙带导通断层对盘的奥灰含水层;奥灰水通过基岩隐伏露头侧向补给矿井。其防治对策为:引进先进技术手段,探查分析奥灰岩溶水发育规律;分区隔离开采,完善防排水系统;注浆封堵突水通道;排供结合,综合利用。      

Numerical simulation of groundwater under complex karst conditions and the prediction of roadway gushing in a coal mine: a case study in the Guang’an Longtan Reservoir in Sichuan Province,China

Numerical simulation of groundwater in karst areas has long been restricted by the difficulty of generalizing the hydrogeological conditions of reservoirs and of determining the relevant parameters due to the anisotropy and discontinuity of the karst water-bearing media in these areas. In this study, we used the Guang’an Longtan Coal mine in Sichuan as an example, and generalized the complex hydrogeological conditions in the reservoir area. A finite element numerical flow model was used to simulate current and future scenarios of roadway gushing at the bottom of the coal mine at pile number 1 + 700 m. The results show that the roadway section corresponding to valleys has a gushing quantity of 4323.8–4551.25 m³/d before impoundment. Modeled water inflow after impoundment increased to 1.6 times the water inflow before impoundment, which threatens the impoundment as well as the roadway’s normal operation. Therefore, roadway processing measures are needed to guarantee the safety of the impoundment and of the mining operation.     

Characterization of the shallow groundwater system in an area with thin soils and sinkholes

Door County, Wisconsin, is a region of karst topography underlain by Silurian dolomite bedrock. Numerous sinkholes intercept much of the surface runoff and act as sites for direct groundwater recharge. The clay-rich and impermeable Upper Ordovician Maquoketa formation separates the dolomite aquifer from the deeper aquifers and appears to be a factor in groundwater circulation and karst formation Thin glacial drift and Quaternary materials overlie the dolomite and are hydrologically connected with it The interactions of surface and groundwater, and the role of solution features in water interchange were studied in a small drainage basin. This basin contains several large sinkholes and a nearby spring complex Mapping identified many additional sinks and swallets in surface drainage routes Water flowing into two sinks was traced and found to have a residence time of several hours. Water flowing into sinkholes and from the spring was sampled to identify the quality and seasonal trends in composition of the shallow groundwater Water quality parameters monitored include magnesium, sodium, potassium, chloride, phosphorous, nitrate and ammonia, nitrogen, alkalinity, pH, turbidity, and specific conductance. Nitrate levels were found to increase 5 to 6 times during periods when there was zero input through sinkhole recharge sites. Nitrate levels approached the 10 mg/l NO₃ ⁻-N limit set by the U.S. Public Health Service for drinking water In this basin sandy soils are most susceptible to sink development, whereas clay-rich soils have a lesser number of sinks. It appears, however, that a network of bedrock solution features exists under all soils The loss of soil into sinkholes has impacted groundwater quality and reduced agricultural productivity through a reduction in tillable acreage and water retention capacity.     

Modeling hydrological responses of karst spring to storm events: example of the Shuifang spring (Jinfo Mt., Chongqing,China)

Reproduction of hydrographs at karst springs has been an approach of understanding the karst aquifer, which normally acts as drains for the groundwater flow. However, its numerical modeling is difficult since factors for the internal geometry and connectedness are unknown and hard to quantify. Hydrographs of the karst aquifer with well-developed conduits in Shuifang spring catchment were obtained from the automatic gauging station at the spring orifice. Data as to the conduit system were also obtained based on results and analyses of tracer tests. With these data, the hydrological responses of Shuifang spring to storm events were simulated by storm water management model (SWMM) developed by USA EPA (Environmental Protection Agency). Nash–Sutcliffe efficiencies are used to compare the computed flow to the observed, which are 0.95 and 0.92 for calibration and validation. SWMM was verified and applicable in karst conduit drainage system. The model illustrated correctly quick recharge through conduits and slow and low inflow from the fissured aquifer matrix. The SCS-CN (soil conservation service-curve number) infiltration method was used for computation of losses and runoff. Field tests indicated that permeability was extremely high but different in karst area, which was less sensitive to the computed runoff when exceeded the common value provided by SWMM. Therefore, an improved quantitative infiltration model for karst area will make SWMM possible to be a useful tool for assessing and reproducing spring hydrographs.     

矿坑排水与岩溶地面塌陷的关系

浙江省某岩溶矿区南部洼地先后发生6处地面塌陷,引发了当地居民的恐慌。矿区排水是唯一地下水开采活动,为分析塌陷区与矿区之间的水力联系,遂在研究区全面布置地下水监测系统。通过对比分析观测水位、矿坑排水量及当地降雨量数据,探讨地面塌陷与矿区排水之间的关系及其潜在成因。研究表明,研究区岩溶地下水动态变化整体保持一致,受降雨、矿坑排水等综合因素影响。北部矿区和南部洼地存在岩溶连通管道,两者在雨季水力联系微弱、旱季水力联系密切。经长期径流潜蚀作用,〖JP2〗导致区内地面塌陷区灰岩顶板岩溶发育处上覆土层出现土洞,当矿区排水量急剧增大时,南部洼地岩溶水位大幅度下降,使得土洞中出现负压、上覆土层所受浮托力降低、孔隙水与岩溶水补排关系改变,在多种效应共同作用下,土洞最终形成地面塌陷。