某铁路隧道隧址区水文地质条件分析与洞身涌水量预算

通过详细分析隧道址区水文地质资料,认为石炭系灰岩、三叠系中统河湾组白云质灰岩和上统大水塘组下段安山玄武岩为强含水层组,大量的岩溶发育于石炭系灰岩和三叠系中统河湾组白云质灰岩中。以井水断层及太元背斜为界,将研究区分为太元背斜和街子坡复式向斜2个水文地质单元,并对各单元中水量、水质与地下水的补给、径流及排泄条件等进行了说明。采取并测试了13组地下水同位素样品,结果发现,区内地下水均来源于大气降水。应用地下水动力学和降水系数法对隧道洞身的涌水量进行了预测,推断隧道的正常涌水量为56 880m3/d,最大涌水量为68 300m3/d。为防止隧道塌方,提出了"短进尺、快循环、弱爆破、少扰动、紧封闭、超前注浆"的施工方法,并要求在施工中做好超前地质预测工作。     

Preliminary evaluation of hydrochemistry of the Kalambaina Formation, Sokoto Basin, Nigeria

Hydrochemical investigations in the Kalambaina Formation have been initiated to determine potability and suitability of the shallow groundwater for domestic and agricultural uses. This limestone formation is an extensive aquifer supplying water to livestock and domestic wells in its outcrop areas. The aquifer is recharged by rainfall and discharges mainly into the Sokoto–Rima River system and lakes at Kware, Gwadabawa and Kalmalo in Nigeria. Because recharge to the aquifer is mainly from rainfall, the quality of the groundwater is controlled essentially by chemical processes in the vadose zone and locally by human activities. Water samples were taken at 11 sites comprising boreholes, dug wells and a spring and were chemically analysed for their major ion components. Hydrochemical results show water of fairly good quality. It is, however, hard and generally of moderate dissolved solids content. Concentration of the total dissolved solids is between 130 and 2,340 mg/l. Concentrations of ions vary widely but a high concentration of K⁺ is found in places. NO₃⁻ is on the higher side of the World Health Organization (WHO) permissible limits, indicating pollution in such areas. Groundwater chemistry is predominantly of two facies, namely the calcium–magnesium–bicarbonate and calcium–magnesium–sulphate–chloride facies. These facies probably evolved primarily as a result of dissolution of calcium and magnesium carbonates as well as some human/land-use activities.     

娘子关泉域岩溶水SO42-、δ34S特征及其环境意义

在分析区域地质、水文地质条件及水化学同位素的基础上,研究了山西娘子关泉域岩溶水的SO42-、硫同位素分布特征。研究表明:（1）泉域西北、西南地区岩溶水的SO42-主要来源于石膏的溶解;（2）泉域中部汇流区岩溶水的SO42-含量高而δ34S值低,其中的SO42-主要来源于煤系矿坑水,这是因为温河、桃河及南川河沿岸的岩溶水接受了被矿坑水污染的河水的渗漏补给以及部分地区受到钻孔串层污染;（3）娘子关泉群中城西泉水中的SO42-主要来源于煤系矿坑水,而五龙泉和集泉站水中的SO42-主要来源于石膏的溶解;（4）泉域东北部及东部河流沿岸以外的地区,岩溶水中的SO42-主要来源于大气降水、石膏溶解,并受到所处地层岩性的影响。      

Geological structure, recharge processes and underground drainage of a glacierised karst aquifer system, Tsanfleuron-Sanetsch, Swiss Alps

The relationships between stratigraphic and tectonic setting, recharge processes and underground drainage of the glacierised karst aquifer system ‘Tsanfleuron-Sanetsch’ in the Swiss Alps have been studied by means of various methods, particularly tracer tests (19 injections). The area belongs to the Helvetic nappes and consists of Jurassic to Palaeogene sedimentary rocks. Strata are folded and form a regional anticlinorium. Cretaceous Urgonian limestone constitutes the main karst aquifer, overlain by a retreating glacier in its upper part. Polished limestone surfaces are exposed between the glacier front and the end moraine of 1855/1860 (Little Ice Age); typical alpine karrenfields can be observed further below. Results show that (1) large parts of the area are drained by the Glarey spring, which is used as a drinking water source, while marginal parts belong to the catchments of other springs; (2) groundwater flow towards the Glarey spring occurs in the main aquifer, parallel to stratification, while flow towards another spring crosses the entire stratigraphic sequence, consisting of about 800 m of marl and limestone, along deep faults that were probably enlarged by mass movements; (3) the variability of glacial meltwater production influences the shape of the tracer breakthrough curves and, consequently, flow and transport in the aquifer.     

Pumping-induced Well Hydraulics and Groundwater Budget in a Leaky Aquifer System with Vertical Heterogeneity in Aquitard Hydraulic Properties

In groundwater hydrology, aquitard heterogeneity is often less considered compared to aquifers, despite its significant impact on groundwater hydraulics and groundwater resources evaluation. A semi-analytical solution is derived for pumping-induced well hydraulics and groundwater budget with consideration of vertical heterogeneity in aquitard hydraulic conductivity (K) and specific storage (Ss). The proposed new solution is innovative in its partitioning of the aquitard into multiple homogeneous sub-layers to enable consideration of various forms of vertically heterogeneous K or Ss. Two scenarios of analytical investigations are explored: one is the presence of aquitard interlayers with distinct K or Ss values, a common field-scale occurrence; another is an exponentially depth-decaying aquitard Ss, a regional-scale phenomenon supported by statistical analysis. Analytical investigations reveal that a low-K interlayer can significantly increase aquifer drawdown and enhance aquifer/aquitard depletion; a high-Ss interlayer can noticeably reduce aquifer drawdown and increase aquitard depletion. Locations of low-K or high-Ss interlayers also significantly impact well hydraulics and groundwater budget. In the context of an exponentially depth-decaying aquitard Ss, a larger decay exponent can enhance aquifer drawdown. When using current models with a vertically homogeneous aquitard, half the sum of the geometric and harmonic means of exponentially depth-decaying aquitard Ss should be used to calculate aquitard depletion and unconfined aquifer leakage.     

川南古叙矿区某矿水质特征及对岩溶发育的影响

川南古叙矿区某矿在基建过程中多次揭露大型导水陷落柱或溶洞,导致突水事故。该矿煤系地层底板为茅口组灰岩,岩溶发育,富水性强,为煤层的直接充水含水层。依据地表水和地下水的水质特征,结合连通试验,分析了矿区地表水和地下水的补给关系,并讨论了地下水水质的成因及其对茅口组灰岩岩溶发育的影响。结果表明,地表水水质为含可溶性固体少的HCO3-Ca型水,呈中性—弱碱性;地下水水质以含可溶性固体少的SO4·HCO3-Ca型水为主,呈酸性—中性,次为含可溶性固体少的SO4-Ca型水。地表水与地下水相互补给,呈酸性的地下水水质源于硫铁矿层的溶解和氧化,对茅口组灰岩岩溶发育有强烈的促进作用。此结果对防治矿井水害具有一定的指导意义。     

山西高阳煤矿奥陶系峰峰组含水层赋存特征

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。     

Hydrogeological analysis and salvage of a deep coalmine after a groundwater inrush

This paper presents a case history of the permanent salvage of the Sanhejian Coalmine in China after a sudden groundwater inrush, which includes emergency responses, hydrogeological analyses, and design and performance of bulkheads. The inrush accident occurred in October 2002 in the mined-out area with a high water pressure of 7.6 MPa and a high water temperature of 51°C. The emergency response quickly followed up to provide the time required to perform a detailed hydrogeological analysis to identify the source and pathway of groundwater. The Sanhejian Coalmine is geologically located in the Tengxian anticline hydrogeological setting. The Sunshidian fault, the northern boundary of the mine, was assumed impermeable in the original hydrogeological report. After the accident and hydrogeological analysis, this assessment was revised and the fault was considered to be permeable. The Sunshidian fault connects the strata in the mine and the excellent water-productive Middle Ordovician Majiagou Formation in the core of the Tengxian anticline. It was concluded that the water inrush was from the underlying Ordovician karst aquifer and the pathway was a hidden tectonic structure in the strata overlying the aquifer. This assessment served as the guideline for salvaging the mine in this project. After a detailed technical and economic analysis, a concrete bulkhead design was selected from several alternatives including dewatering and surface grouting. The performance of the bulkheads has been sufficient for the last 6 years since their construction. This case history shows that the hydrogeological analysis plays an essential role in successfully salvaging the coalmine from the water inrush by identifying the source and pathway of groundwater.     

化隆—循化盆地不同类型含水层组高氟地下水的分布及形成过程

天然成因的高氟地下水是世界范围内备受关注的环境问题和饮用水安全问题。前人对高氟地下水的形成过程已开展了大量研究,但是对于高原盆地复杂水文地质条件下不同类型含水层组(第四系松散层含水层、基岩裂隙或岩溶含水层以及新生代古近纪以来的碎屑岩含水层)高氟地下水的分布和形成过程尚不明确。本文以化隆—循化盆地为研究区,通过采集、测试研究区内的各类地下水样品,分析研究区内不同类型含水层中地下水的化学特征及同位素特征。结果表明,高氟地下水(1.007.73 mg/L)主要分布在沿黄河的河谷区域和巴燕低山丘陵区域的泉水和潜水中以及深部的承压水中,在垂向上高氟地下水无明显分布规律。接受黄河水入渗补给的河谷潜水中氟离子浓度较低,补给黄河的河谷潜水中氟离子浓度较高。贫钙富钠的弱碱性苏打型水有利于地下水中氟的富集。泉水和潜水中氟主要来源于萤石的溶解,而承压水中氟除了来源于萤石外,还来源于其他含氟矿物。对于潜水和第四系松散层泉水,蒸发浓缩作用促进了地下水中氟的富集。另外,阴离子竞争吸附作用、阳离子交换吸附作用是泉水(第四系松散层泉水和基岩裂隙泉水)和潜水中氟元素富集的主要原因,而承压水中氟离子浓度受竞争吸附作用影响较大,阳离子交换吸附作用影响较小。研究成果可为化隆—循化盆地低氟地下水的勘查和开发提供科学依据。     

涞源北盆地地下水氢氧同位素特征及北海泉形成模式

拒马源泉群作为拒马河的源头,受到了较多专家和学者的关注。但这些研究多集中在地下水的水化学、水位动态、泉流量等特征上,对地下水氢氧同位素特征的分析几乎没有,且对北海泉的成因解释多为粗略的定性概述。为了说明涞源北盆地地下水的氢氧同位素特征,详细揭示北海泉的形成模式,首次系统地采集了不同含水岩组的地下水样品,测定了水样的氢氧同位素组分。结果表明:样品点δD和δ18O值均落在区域大气降水线上或附近,大气降水是研究区地下水的主要补给来源;白云岩、灰岩含水岩组高程效应较明显,径流途径长,松散含水层径流途径短,受蒸发作用较强;白云岩、灰岩含水岩组和松散含水层氘盈余d值分别为6.0‰～11.6‰、4.2‰～11.2‰、3.8‰～8.0‰,较大气降水大部分偏小,表明岩溶水和松散孔隙水经历了不同的流动过程;白云岩、灰岩含水岩组从补给区向排泄区各自流动过程中,在小西庄、香炉屯村附近断裂带发生沟通混合,然后在向盆地中心径流过程中受断层阻水上升,上升过程中又接受了松散孔隙水的补给,最后在松散岩层中出露成泉,形成北海泉。在孔隙水混入前,两者的平均补给比例大约为48.4%～57.6%和42.4%～51.6%。     

Geology and hydrogeology of the Dammam Formation in Kuwait

 The Dammam Formation of Middle Eocene age is one of the major aquifers containing useable brackish water in Kuwait. Apart from the paleokarst zone at the top, the Dammam Formation in Kuwait consists of 150–200 m of dolomitized limestone that is subdivided into three members, on the basis of lithology and biofacies. The upper member consists of friable chalky dolomicrite and dolomite. The middle member is mainly laminated biomicrite and biodolomicrite. The lower member is nummulitic limestone with interlayered shale toward the base. Geophysical markers conform to these subdivisions. Core analyses indicate that the upper member is the most porous and permeable of the three units, as confirmed by the distribution of lost-circulation zones. The quality of water in the aquifer deteriorates toward the north and east. A potentiometric-head difference exists between the Dammam Formation and the unconformably overlying Kuwait Group; this difference is maintained by the presence of an intervening aquitard. Received, February 1997 Revised, June 1997, September 1997 Accepted, January 1998     

上海市地下水位大幅抬升条件下土层变形特征分析

过去对地下水位持续下降条件的地面沉降研究较多,但对水位大幅持续抬升过程中的地面沉降研究较少。本文根据 上海大量地面沉降、水位观测和钻孔资料,系统分析上海市90年代末以来地下水位大幅抬升条件下各土层的变形特征。自 1998年以来,上海市通过大幅压缩开采量、回灌地下水等措施使第二、三、四和五承压含水层水位分别平均抬升2.1 m, 3.6 m, 12.4 m, 12.7 m。水位的抬升使上海市地面沉降平均速率由1998年的12.2 mm/a减小到2011年的1.83 mm/a,减少85%。 通过对27组分层标数据分析发现：现阶段主要压缩层位在第一、二软土层,年沉降速率为2~4 mm/a;而第二含水层以下土 层已经有少量回弹。在水位持续大幅抬升过程中,本文总结了两种变形特征：1） 变形和水位变化基本同步,残余变形量非 常小,变形可概化为线弹性变形,这种变形主要发生在第一、二、三和五承压含水层、第五和六弱透水层;2） 压缩速率逐 渐减小,无明显持续回弹趋势,有较大残余压缩量且存在变形滞后现象,变形可概化为弹塑性变形,这种变形主要发生在 地第二、三和四弱透水层。第四承压含水层变形较复杂,两种变形特征都有。其中较大残余变形量主要由塑性贮水率比弹 性贮水率大2个数量级引起;变形滞后主要由弱透水层中超孔隙水压力消散较慢引起。本文研究成果对于掌握水位抬升过 程中土层变形方式、发生发展机理、预测未来地面沉降及地下水科学管理和资源评价具有重要意义。     

The relationship between the water table and the surface flow of a losing stream, lower Medano Creek, Great Sand Dunes National Monument, Colorado

 Proposed groundwater withdrawals in the San Luis Valley of Colorado may lower the water table in Great Sand Dunes National Monument. In response, the National Park Service initiated a study that has produced a generalized conceptual model of the hydrologic system in order to assess whether a lowering of the water table might decrease the surface flow of lower Medano Creek. Based upon information obtained during the drilling of several boreholes, there appear to be five important hydrostratigraphic units underlying lower Medano Creek within the upper 30 m of the ground surface: 1. a perched aquifer overlying an aquitard located between about 5 and 6 m below the ground surface; 2. the aquitard itself; 3. an unconfined aquifer located between the upper and lower aquitards; 4. an aquitard located between about 27 and 29 m below the ground surface; and 5. a confined underlying the lower aquitard. Because the areal extent of the aquitards cannot be determined from the borehole data, a detailed conceptual model of the hydrogeologic system underlying lower Medano Creek cannot be developed. However, a generalized conceptual model can be envisioned that consists of a complex system of interlayered aquifers and leaky aquitards, with each aquifer having a unique hydraulic head. Water levels in the perched aquifer rise rapidly to their annual maximum levels in response to the arrival of the flow terminus of Medano Creek during the spring runoff event, and the location of the flow terminus is directly dependent upon the discharge of the creek. Water levels in the deeper, non-perched aquifers do not appear to fluctuate significantly in response to the arrival of the flow terminus, demonstrating that it is unlikely that the proposed groundwater withdrawals will decrease the surface flow of lower Medano Creek. Received: 27 December 1995 · Accepted: 20 February 1996     

焦作煤矿区岩溶水水位统计模型研究

针对研究区地下水系统结构等资料不完备,本文基于质量守恒原理和微积分原理,建立了地下水水位统计预测模型和水位延迟模型,并在焦作矿区得到验证。焦作矿区岩溶地下水对于降水响应结果表明,当延迟时间为10个月时,岩溶地下水水位与降水的相关系数最大,为0.83,而延时2个月和5个月时,相关系数分别只有0.71和0.78;模型观测孔水位预测结果表明,相关系数超过0.9的观测孔达60 %,相关系数超过0.8的观测孔则高达95 %;模型水位影响因素分析结果显示,在降雨、矿坑排水、地下水蒸发3个影响因素中,煤矿区岩溶地下水水位动态对降雨量响应最敏感,说明降雨量,尤其是长期稳定的补给量是地下水水位最主要的影响因素。该类模型适用性强,简易方便,有广阔的应用前景。      

济宁煤田一区奥陶系第六段灰岩水综合利用的探讨

奥 陶 系石 灰 岩 是 济宁 煤 田 一 区太 原 组 下 部煤 层 底 板 充水 含 水 层 ,岩 溶 裂隙 发 育 ,富 水 性 较 强,由 于排 泄 条 件差, 天然 状 态下 水质 不 符合 饮用 水标 准 。通 过 群孔 抽 水 试 验,改 变 了地 下 水 的 循环 条 件 ,使 水 质 达 到了 生 活 用 水 导致标 准,为此 区 奥灰 水的 综 合利 用打 下 了基 础。     

川东断褶带仙女山温泉地质成因浅析

川东断褶带背斜高陡,沿断褶带泉眼众多,流量丰沛。受构造裂隙和河流切割的双重作用,在河流切割低点多可见温泉出露。仙女山温泉位于川东断褶带铜锣峡构造最北端三叠系下统须家河组砂岩地层中的浅表裂隙当中,泉眼温度38~40℃,泉口有青绿色泉华沉淀。用地温梯度法估算出地下水循环深度略大于1000m。对比当地地层为嘉陵江组的深层地下水,结合区域地质构造,认为仙女山温泉地下水沿着高渗透率岩溶裂隙岩层上升成泉。     

Formation of regolith-collapse sinkholes in southern Illinois: Interpretation and identification of associated buried cavities

Three regolith-collapse sinkholes formed near the Dongola Unit School and the Pentecostal Church in the southern Illinois village of Dongola (Union County) during the spring of 1993. The sinkholes appeared over a three-month period that coincided with development of a new municipal well. The new well was drilled through clay-rich, valley-fill sediment into karstified limestone bedrock. The piezometric surface of the limestone aquifer is above land surface, indicating the presence of an upward hydraulic gradient in the valley and that the valley fill is acting as a confining unit. Pumping during development of the well lowered the piezometric surface of the limestone aquifer to an elevation below the base of the valley fill. It is hypothesized that drainage of water from the sediments, the resulting loss of hydrostatic pressure and buoyant force in overlying sediments, increased intergranular pressure, and the initiation of groundwater flow toward the well resulted in rapid sediment transport, subsurface erosion, and collapse of the valley-fill sediment. The sinkholes follow an approximately east-west alignment, which is consistent with one of the two dominant alignments of passages of nearby joint-controlled caves. A constant electrode-separation resistivity survey of the school playground was conducted to locate areas that might contain incipient sinkholes. The survey revealed a positive resistivity anomaly trending N75E in the southern part of the study area. The anomaly is linear, between 5 and 10 m wide, and its trend either intersects or is immediately adjacent to the three sinkholes. The anomaly is interpreted to be a series of pumping-induced cavities in the valley-fill sediments that formed over a preexisting crevice in the karstified bedrock limestone.     

Sensitivity analysis for the EPIK method of vulnerability assessment in a small karstic aquifer, southern Belgium

Applying the EPIK parametric method, a vulnerability assessment has been made for a small karstic groundwater system in southern Belgium. The aquifer is a karstified limestone of Devonian age. A map of intrinsic vulnerability of the aquifer and of the local water-supply system shows three vulnerability areas. A parameter-balance study and a sensitivity analysis were performed to evaluate the influence of single parameters on aquifer-vulnerability assessment using the EPIK method. This approach provides a methodology for the evaluation of vulnerability mapping and for more reliable interpretation of vulnerability indices for karst groundwater resources. Received, March 1999/Revised, December 1999, February 2000/Accepted, February 2000     

淮北矿区五沟煤矿太原组上段灰岩岩溶裂隙水富水性及径流特征

五沟煤矿太原组上段灰岩岩溶裂隙水是矿井主采煤层（10煤）的主要充水含水层。通过对矿区水文地质边界条件、地面抽水试验和井下放水试验的分析,认为矿区水文地质边界受制于周边的较大型隔阻水断层,从而形成了较封闭的地下水系统;太原组上段灰岩含水层的富水性在平面上具有不均一性,在垂向具有随着深度的增加,岩溶发育有减弱的趋势,基本上属弱富水含水层,仅在局部构造发育带为中等富水含水层。利用利用surfer软件,绘制出矿区太原组灰岩水位等值线图;从图上可以看出,矿区目前太原组含水层水位标高总体呈北高南低,中间高两边低的态势,并在井田西南部形成以水5孔及J5-1孔为中心的低水位区。该研究对目前矿井防治水工作具有重要的指导意义。     

山西省离柳矿区沙曲井田数值模拟及矿井涌水量预测评价

沙曲井田位于山西河东煤田离柳矿区的中部,处在柳林泉域岩溶水系统的径流区。矿区奥灰水水量大,水位标高为+797～+802m,其中的4#煤底板承受奥灰水压2～5MPa,10#煤底板承受奥灰水压3～6MPa,属带压开采矿井。利用井田以往的地质及水文地质勘探资料,应用GMS软件建立矿区三维立体模型和地下水渗流的数学模型,实现水文地质结构三维可视化,使数学模型能正确地反映预测区的水文地质条件,达到数值仿真效果;应用有限差分数值法,对开采上组煤(3#+4#)和下组煤(8#+9#、10#)时,石炭系太原组灰岩含水层和奥陶系峰峰组含水层的疏降进行矿井涌水量预测,为矿井的安全生产和防治水工作提供依据。