单一流径基岩裂隙水平均流速试验研究

根据室内模拟试验数据研究了单一流径基岩裂隙水流的平均流速，建立了单一流径无压裂隙水和承压裂隙水的平均流速与不力坡度之间的回归方程。     

基于阶梯流量压水试验水位恢复的含水层参数计算

承压含水层阶梯流量井流公式与水位恢复井流公式可解决不同流量变动条件下含水层参数求解。针对野外压水试验中流量与水压难以控制且观测精度低, 但阶梯流量压水后水位恢复曲线易于准确观测的特点, 根据叠加原理, 从非稳定承压含水层阶梯流量井流基本公式中推导出阶梯流量水位恢复公式。根据现场阶梯流量压水试验资料进行了含水层参数计算, 验证了公式的可行性。     

内蒙古官地银金矿床基岩裂隙水赋存特征及混合抽水试验分析

官地银金矿床基岩风化裂隙和断裂构造裂隙发育 ,基岩裂隙水由风化裂隙水和构造裂隙脉状水组成。脉状水与风化裂隙水相沟通 ,形成一个具有统一水位的裂隙含水系统 ,钻孔混合抽水试验也证明了基岩裂隙水这一赋存特征     

基岩三维流数学模型求解的广义差分法及应用

白垩系基岩孔隙裂隙承压含水层为研究区地下水主要含水层之一,水文地质模型概化为各项异性非均质.根据地下水系统运动规律及分布特征建立三维非稳定流数学模型,采用广义差分法对其求解,并以长春市区为例对模型进行识别验证.结果表明,计算模型与实际水文地质条件比较接近,计算水位与实测水位相吻合;为研究区地下水系统可持续管理提供了科学理论依据.     

壁面局部接触裂隙岩体水流-传热的一种理论模型及计算分析

核废物地质处置、地热开发、石油开采等工程领域都可能涉及稀疏裂隙岩体中的水流-传热过程。现有的裂隙岩体水流-传热理论模型和计算方法基本上都是以平行光滑壁面裂隙模型为基础的,没有考虑裂隙的壁面局部接触对水流、水-岩热交换以及岩体传热的影响。针对粗糙壁面裂隙水流过程,阐述了基于Stokes方程的Reynolds润滑方程及Hele-Shaw裂隙模型,采用MATLAB软件中的PDE工具求解,并与Walsh的等效水力开度公式进行对比;分析壁面局部接触裂隙水流-传热与填充裂隙水流-传热的相似性,提出了瞬时局部热平衡假设的适用条件,并在裂隙局部接触体传热满足Biot数条件的前提下,计算分析裂隙局部接触体与水流之间的局部热平衡时间及其影响因素;在裂隙局部接触体与水流之间满足瞬时热平衡假设的前提下,利用填充裂隙水流-传热的解析解,计算了壁面局部接触裂隙水及两侧岩石的温度分布,并分析了裂隙局部接触面积率、裂隙开度、裂隙水平均流速对岩石温度和裂隙水温度的影响特征,结果表明：（1）在设定条件下,由于裂隙局部接触体与裂隙水流之间的热交换,裂隙水流对其两侧岩石温度的影响范围随接触面积率的增大而减小,裂隙两侧岩石对裂隙水流温度的影响程度随接触面积率的增大而增大;（2）裂隙开度和裂隙水流速对岩石温度和裂隙水温度的影响方式的影响是一致的,即由于裂隙水流量随裂隙开度和裂隙水流速的增大而增大,裂隙水流对其两侧岩石温度的影响范围随裂隙开度和裂隙水流速的增大而增大,裂隙两侧岩石对裂隙水流温度的影响程度随裂隙开度和裂隙水流速的增大而减小。     

日照市地下水动态特征及演化规律

文章首先介绍了日照市监测站的发展,然后根据区域水文地质条件,将日照市地下水类型分为碎屑岩类孔隙裂隙水、碳酸盐岩类裂隙岩溶水及基岩裂隙水4个含水岩组,并根据日照市多年地下水监测数据,选取了有代表性的4个监测点分析了日照市地下水水位动态特征,进而总结出水位的演化规律：日照市地下水水位受大气降水和开采量的影响较大,多年呈波浪起伏状态;选取了7个监测点分析了日照市地下水水质动态特征,总结出水质的演化规律：氯含量逐年升高和水平分带性,人类活动是本区地下水水质变化的直接因素,为合理开发利用地下水资源与国民经济发展提供科学依据。     

滇西地区基岩裂隙水的富集规律

基岩裂隙水是云南省五大地下水类型之一。滇西地区蕴藏着丰富的基岩裂隙水。本文就已完成的该地区十余个1:20万或1:50万的水文地质调查图幅和1:5万供水勘察的资料为依据,着重讨论了区内地层岩性和地质构造对基岩裂隙水富集的影响及控制作用。本文从富水结构类型分析研究出发,总结了沉积碎屑岩、坚硬性脆的变质岩及风化岩浆岩在各种类型的节理裂隙和结构空间介质良好的条件下,赋存基岩裂隙水的结构特征,研究了各类地质构造形态有利部位富集基岩裂隙水的基本条件。具体划分了区内基岩裂隙水的富水结构类型,特别对褶皱构造的不同部位,不同性质断裂破碎带、交汇带、影响带,各构造体系的复合部位的阻水富水条件进行了探讨,突出了富水结构特征和形成机理的阐述,归纳出一些基岩裂隙水的富集规律。以期能对寻找和开发利用这类地下水资源,以解决干旱地区分散农田和居民的供水问题,起到一定的宏观指导意义。     

劈裂砂岩有、无砂粒填充条件下的多因素对渗流量影响对比分析

采用宜昌劈裂砂岩,在有、无砂岩填充条件下,分别从轴压、围压、劈裂面面积、凹凸高差、迹线长度、劈裂面2D投影面积、进出口长度、结构面粗糙度对渗流量的影响规律进行了对比分析。研究结果表明：有、无砂粒填充下轴压与渗流量均呈线性递增关系;无填充时围压与渗流量呈对数递减关系,有充填时围压与渗流量呈线性关系;无充填时渗流量与流面积呈三次函数关系,而充填后过流面积对渗流量几乎无影响;凹凸高差、2D面积与渗流量的关系也有相似规律,分析认为,这主要是砂粒充填后带来的过流通道要远大于上述三因素对过流通道的改变;无充填时,渗流量随迹线长度线性递减,有填充时该规律被淹没;无论有、无填充,渗流量与过流面粗糙度系数在一定范围内均呈现二次函数关系。这些规律能指导渗流测量时各因素的优先次序,可有效减少对次要影响因素的测量工作,同时可对渗流的数值模拟提供参考。     

双重介质模型在岩溶地下水流动系统模拟中的应用

文章采用不稳定层状裂隙水流模型,应用有限元-卷积结合法,模拟了岩溶地下水流动系统。相对于等效多孔介质模型,双重介质模型模拟的水位下降速度更小,达到稳定的时间更长。距抽水井较近的观测孔处,双重介质模型模拟的水位变化过程阶段性较明显,水位变化过程类似于承压含水层-弱透水层的释水过程,裂隙和孔隙基质分别相当于承压含水层和弱透水层。然后讨论了影响裂隙和孔隙基质间水流交换项的因素,分析了孔组抽水后的渗流场特征。     

富源大河煤矿三、四矿井区涌水量预测方法比较

矿井涌水为承压裂隙水,运用"大井法"承压水转无压完整井公式,"比拟法"预测煤系和卡以头组地层的矿井涌水量,预测结果进行相互比较验证。     

基岩裂隙水水位沿程变化曲线方程的实验研究

本文根据室内模拟实验，研究了不同条件下隙宽小于3mm单一裂隙基岩水水位沿程变化曲线，验证了孙峰根等人建立的单一裂隙基岩水水位沿程变化的曲线方程。结论对基岩水运动理论的研究具有重要的参考价值。     

小隙（b＜3 mm）单一流径基岩水平均流速的实验研究

根据模拟试验,研究了不同条件下小隙单一流径基岩水的平均流速;对平均流速与水力坡度间的关系进行了统计,建立了回归方程;为验证基岩水壁间运动的平均流速方程提供了的新的实验根据,解决了基岩水壁间运动理论的适用范围问题。      

Competition between topography- and compaction-driven flow in a confined aquifer: Some analytical results

 An analysis is presented of the competition between topography- and compaction-driven flow in a confined aquifer. The aquifer crops out and is unconfined in an area with an elevated water table. In the absence of compaction, the elevated water table drives the flow toward areas with a lower water table, and leakage occurs from the aquifer through an overlying aquitard. Under these conditions, recharge occurs in the outcrop area. When sedimentation occurs above the aquifer away from the outcrop area, compaction tends to reverse the flow direction in the aquifer, causing expulsion of groundwater in the outcrop area. The actual flow field arises from the competition between the two driving mechanisms. An analytical expression for the combined flow field is derived in which the contribution from both mechanisms is apparent. The expression is useful as a practical guideline for estimating whether or not compaction can be safely ignored in regional groundwater-flow studies of confined aquifers. Received, July 1998 / Revised, February 1999 / Acccepted, February 1999     

巨厚松散层下煤层开采的抗渗透性破坏和煤柱安全性研究——以口孜东矿为例

采掘诱发裂隙导通顶板上覆含水砂层中产生的水力坡度是渗透型溃砂的关键判断依据之一,但是,到目前为止主要是采用定流量下的稳定流水力坡度表达式计算,而实际上,上覆含水层中水动力条件和涌水量在溃水溃砂过程中都是非稳定的。本文依据非稳定流理论,给出了二维潜水、承压水单井定降深模型下的水力坡度J的解析公式,并分析了J随时间和距离的演变特征。结果表明,对于潜水,J随与井的距离r的增加而下降,下降速度随r的增加而减小;存在拐点r′,当r<r′时,J随时间延长而下降,在r>r′时,J随时间延长而增加;随着地下水头H₀的增加,J是增加的;本文获得的潜水的非稳定流条件下的J大于潜水稳定流的J。对于承压水,J随r的增加而下降,下降速度随r的增加而减小;与潜水不同的是,在不同r处,J随时间延长而下降,不存在拐点;随着H₀的增加,J是增加的;本文获得的承压水的非稳定流条件下的J不总大于承压水稳定流的J。最后,在伊犁河谷某矿对本文方法进行了初步应用。     

变异条件下内蒙古呼包平原地下水演化趋势

重点探讨气候变异对内蒙古呼包平原地下水资源、地下水流场和动态的影响。在介绍呼包平原水文地质条件的基础上,运用地下水模型软件PMWIN 5.1建立了研究区双层地下水流模型,并根据1998年地下水动态观测和统测资料对模型进行识别。通过对近51 a降水量的分析,确定将连续出现的2个特枯年作为地下水的变异条件,运用地下水模型对变异条件下地下水状态进行模拟,结果表明：2年间对地下水的严重超采,使地下水亏空量达75 296.34 万m³,潜水和承压含水层的地下水位大幅度下降,潜水位最大下降4 m左右,承压水位最大下降17 m左右;漏斗中心主要集中在开采量大的呼和浩特和包头市区。     

Groundwater flow patterns in the San Luis Valley,Colorado, USA revisited: an evaluation of solute and isotopic data

Groundwater systems in the San Luis Valley, Colorado, USA have been re-evaluated by an analysis of solute and isotopic data. Existing stream, spring, and groundwater samples have been augmented with 154 solute and isotopic samples. Based on geochemical stratification, three groundwater regimes have been identified within 1,200 m of the surface: unconfined, upper active confined, and lower active confined with maximum TDS concentrations of 35,000, 3,500 and 600 mg/L, respectively. The elevated TDS of northern valley unconfined and upper active confined systems result from mineral dissolution, ion exchange and methanogenesis of organic and evaporate lake sediments deposited in an ancient lake, herein designated as Lake Sipapu. Chemical evolutions along flow paths were modeled with NETPATH. Groundwater ages, and δ¹³C, δ²H and δ¹⁸O compositions and distributions, suggest that mountain front recharge is the principle recharge mechanism for the upper and lower confined aquifers with travel times in the northern valley of more than 20,000 and 30,000 ¹⁴C years, respectively. Southern valley confined aquifer travel times are 5,000 ¹⁴C years or less. The unconfined aquifer contains appreciable modern recharge water and the contribution of confined aquifer water to the unconfined aquifer does not exceed 20%.     

银川地区承压水水化学特征及控制因素

银川平原属中温带干旱区,蒸发强烈,潜水水质差,承压水是银川市地下水开采的主要水源。通过ArcMap空间分析、传统作图分析、氢氧同位素分析等方法,分析银川地区承压含水层水化学特征及各含水层水化学特征的差异,探讨了承压水水化学分布特征的控制因素。研究表明,潜水和承压水水化学分布特征在水平和垂直方向上均存在较大差异;第一和第二承压水水化学分布特征在水平方向上相似,在垂直方向上存在一定差异。水平方向上,两层承压水水化学特征存在一定分带性,而潜水无明显规律性。两层承压水在靠近西侧补给区溶解性总固体（TDS）较小,阴离子以HCO-3为主,阳离子以Mg2+和Ca2+为主,向东溶解性总固体逐渐增加,在银川断裂附近,阴离子变为以Cl-和SO2-4为主,阳离子以Na+为主。垂向上,由于银川断裂贯穿承压和潜水含水层,且潜水水位高于承压水位,第二承压水可能主要受到更深层地下水沿着断裂的混入作用,第一承压水可能同时受到更深层地下水和潜水的混入,使得在银川断裂附近,部分第二承压水TDS大于第一承压水,且具有更高含量的Na+和Cl-,及更低含量的Ca2+和HCO-3,也有部分第一承压水TDS大于第二承压水,该部分第一承压水中的个别水样TDS大于潜水。由此得出,银川断裂的发育及其对潜水及承压含水层的贯通作用是控制该区地下水水质的一个重要因素。如果承压水继续过量开采,承压水位持续下降,将进一步激发潜水和更深层地下水的混入,从而导致承压水质恶化。因此控制银川区承压水的过量开采,对于承压水资源的可持续利用至关重要。     

A practical and efficient numerical scheme for the analysis of steady state unconfined seepage flows

The scaled boundary finite‐element method (SBFEM), a novel semi‐analytical technique, is applied to the analysis of the confined and unconfined seepage flow. This method combines the advantages of the finite‐element method and the boundary element method. In this method, only the boundary of the domain is discretized; no fundamental solution is required, and singularity problems can be modeled rigorously. Anisotropic and nonhomogeneous materials satisfying similarity are modeled without additional efforts. In this paper, SBFE equations and solution procedures for the analysis of seepage flow are outlined. The accuracy of the proposed method in modeling singularity problems is demonstrated by analyzing seepage flow under a concrete dam with a cutoff at heel. As only the boundary is discretized, the variable mesh technique is advisable for modeling unconfined seepage analyses. The accuracy, effectiveness, and efficiency of the method are demonstrated by modeling several unconfined seepage flow problems. Copyright © 2011 John Wiley & Sons, Ltd.     

稳定井流直线图解法确定含水层参数

对于潜水井流,利用Dupuit公式计算的参数往往相差很大,难以直接选用。对Dupuit公式进行线性化,建立降深(s)与距离(r)的s-lnr直线关系,利用直线斜率、直线在x轴上的截距,可以直接求得唯一的渗透系数K和影响半径R。利用松花江河谷的承压水井抽水试验资料和洮儿河扇形地27个潜水抽水井及其观测孔的抽水试验资料,应用直线图解法分析计算,得到唯一的含水层参数T、K和R。将计算结果与直接利用Dupuit公式所计算的结果相比较,前者的求参效果较好。     

Synthesizing multifaceted characterization techniques to refine a conceptual model of groundwater sources to springs in valley settings (Minnesota,USA)

Springs are commonly used as low-cost monitoring locations to assess groundwater quality and long-term trends. However, spring waters in many settings are a mixture of groundwater sources that range in physical properties and water chemistry. The objective of this work was to determine water sources of springs emerging from the North American midcontinent Cambrian-Ordovician aquifer system at a fish hatchery near Lanesboro, Minnesota (USA), and compare and contrast the sources to shallower and deeper sources. The hydrology of the Lanesboro State Fish Hatchery has been studied for decades using a combination of dye tracing, thermal monitoring, geochemical sampling, and nearby borehole and outcrop observations. Previous studies are integrated with recently collected dye tracing results and geochemical data to develop a comprehensive conceptual model of groundwater flow. Dye trace findings and geochemistry indicate well-developed karst and bedrock fractures in shallowly buried unconfined carbonate formations are important transport pathways to convey anthropogenically influenced waters from the land surface to the hatchery springs. However, borehole dye traces, thermal monitoring, continuous nitrate monitoring, and mixing calculations show that a deeper confined siliciclastic aquifer is responsible for delivering relatively pristine water that accounts for about half of hatchery spring flux. Characterization of the hatchery’s groundwater systems provides fishery managers with information to protect this vital resource and improved context to interpret water-quality-monitoring data that track agricultural contaminants. The methods and results of this study may be widely applicable across a large extent of the Cambrian-Ordovician aquifer system, and to multiaquifer sedimentary bedrock systems elsewhere.