干旱区坎儿井与山前凹陷地下水库

在分析研究坎儿井主要技术特点的基础上,结合河流冲洪积扇地形地貌特征、储水构造以及水资源转化特点,提出了建设山前凹陷带"横坎儿井式"地下水库的具体思路,并以台兰河地下水库示范工程为例,对构筑"横坎儿井式"地下水库的可行性及其"引渗回补"调蓄系统、"横坎儿井"集水系统、"自流虹吸"输水系统三大工程组成部分的结构设计原理进行了初步的探讨.山前凹陷地下水库是非常理想的应急抗旱水源工程,其研究和示范工程,为干旱区内陆河流域地表水与地下水联合调度、水资源高效利用探索出了一种新模式.     

地下水示踪技术在水库渗漏勘察中的应用

岩溶库区渗漏及坝基渗漏勘察往往需要投入大量人力财力和技术。给出了岩溶库区与坝基地下水渗漏勘察的3个实例,对典型岩溶库区渗漏进行的示踪试验表明,渗漏主要受库岸岩溶发育程度控制,水库蓄水水位剧烈变动成为诱发渗漏的主导因素,随着库区水位平稳及河流泥沙对库岸溶洞的淤填,渗漏会随之减弱。典型水库砂砾石坝基渗漏示踪试验显示,渗漏具有主渗通道。示踪成果为水库防渗加固治理提供重要依据。大型示踪试验是一项复杂的勘察工程,把握示踪试验过程与质量监控是取得成功的关键。      

陆浑水库坝基水位观测资料分析

经过对 30余年水位观测资料的整理和分析 ,在厘定水文地质模型的基础上 ,运用数理统计原理 ,获得了坝基地下水渗流特征及其变化趋势的基本认识 ,这包括库、管水位关系 ,代表断面测压管平均位势过程线 ,特定库水位时测压管管水位过程线 ,坝基渗流量变化。研究表明 ,上游铺盖与截水槽结合下游排水的防渗体系有效地控制了坝基水位 ,这为水库投入正常高水位(319.5 ,32 7.5 ,331.8m)的运行提供了详实的理论依据。     

澧水流域皂市水利枢纽工程地质评价

本文对皂市水利枢纽的区域稳定性和水库渗漏、浸没、库岸稳定性,矿产淹没以及坝基岩体性状、软弱夹层、坝下冲刷、下游右岸滑坡等工程地质条件与问题进行了全面的分析与评价,结论是库区地形地质条件优良,存在的地质问题易于解决。     

Electrical resistivity imaging and dye tracer test for the estimation of water leakage paths from reservoir of Akdeğirmen Dam in Afyonkarahisar,Turkey

The seepage occurrence from the reservoir on the right bank of the Akde?irmen Dam located in Afyonkarahisar province in the Turkey has been investigated. When the reservoir began to fill with water, a large amount of water seepage occurred at the dam. The seepage developed at the base of the spillway and the right downstream slope of the dam. The various attempts have been made to reduce the seepage using grouting. Although the additional grouting operations was reduced the seepage at the base of the spillway, there has not been a reduction in seepage at the water outlet location at the downstream slope. Electrical resistivity measurements along the eight lines with the dipole–dipole array and dye tracer tests were performed in order to identify the seepage locations. The interpretation of electrical resistivity data showed the distribution of strata and the seepage zone along the right downstream of the dam. Groundwater flow rates calculated from dye tests indicated that there is an excessive seepage south-eastwardly on the downstream slope of the dam. Integrated interpretation of resistivity data and dye tests indicate that the seepage paths are in the direction from NW to E and SE.     

屋檐洞溶洼水库坝体工程条件与渗漏分析

溶洼成库，是岩溶区地下水开发的主要途径之一。屋檐洞溶洼水库是封堵地下河形成的地下、地表联合水库，堵体位于距地表182m的地下河道中。除主体工程外，坝体上部有厚110m的松散堆积作为天然坝体。通过实地勘测、钻探及物探等成果资料和地下河试堵工程观察分析，上部松散体主要由滑坡堆积而成。本文对滑坡体的成因条件和坝体工程地质特征进行分析，认为滑坡是由水流冲刷、地貌、岩体结构及外应力等的共同作用产生的，对坝体的稳定具有一定的影响，但滑坡体渗漏是成库的关键。按不同渗漏条件，可分为上部松散体及岩溶裂隙和层间错动带的渗漏，渗漏点分布于550m高程以上。通过研究，该坝体在采取相应工程措施处理的基础上，蓄水高程可达650m左右，可形成以地下河道为主要蓄水空间的溶洼水库。     

房县深峪沟病险水库黏土心墙坝稳定性分析

以房县深峪沟病险水库黏土心墙坝为研究对象,对其渗流稳定和坝坡稳定性进行评估,目的是为加固设计提供参考。设计了校核洪水位、设计洪水位、正常蓄水位的稳定渗流计算,校核洪水位降到正常蓄水位、正常蓄水位降到死水位的非稳定流计算工况,其中正常蓄水位降到死水位的工况又设计了5种降速计算方案,利用自动搜索滑动面的Morgenstern-Price法计算了不同工况下的坝坡稳定性,分析发现：校核洪水位稳定渗流背水坡安全系数k＜1.15,不满足工程稳定性要求;设计洪水位和正常蓄水位工况,安全系数k＜1.25,不满足工程稳定性要求。校核洪水位到正常蓄水位的迎水坡满足k≥1.15的要求,背水坡不满足k≥1.15的要求;正常蓄水位到死水位迎水坡在设计的5种降速下均存在时间步不满足k≥1.25的要求,所以该水库属于病险库,需要加固处理     

绕坝渗流地下水位的时空分布模型研究

许多大坝的失事是由于高地下水位引起坝肩失稳所致。绕坝渗流是影响坝肩高地下水位的主要因素。为此通常将大坝基础防渗帷幕延伸到坝肩岸坡内一定距离,以减小绕坝渗流影响。而防渗帷幕运行性态随时间变化,为了评价坝肩防渗帷幕和地下水位的运行性态,首先分析了地下水位观测资料和水位、降水、温度、时效等时空影响因素及其表达式,随后基于岸坡地下水位观测资料,利用最小二乘法建立了大坝岸坡地下水位的时空分布模型。通过比较模型剩余标准差和测点的剩余标准差,可以确定坝肩地下水位的异常测点,分析岸坡防渗薄弱部位,掌握坝肩岸坡渗流场时空分布规律,监控绕坝渗流的性态。     

Assessment of water seepage through a geologic barrier surrounding a large reservoir using groundwater levels, soil condition, and a numerical model

Though the geologic barrier surrounding a dam reservoir plays an important role in preventing water seepage to the outside of a reservoir, a detailed survey to assess bedrock conditions of the whole reservoir boundary is seldom performed when designing a dam. In this study, a variety of investigations and analyses have been conducted to reveal a seepage phenomenon through a reservoir boundary composed of highly fractured metamorphic rocks at the Daechung multipurpose dam. At the study site, groundwater levels at monitoring wells located close to a reservoir tend to change proportionally to reservoir water levels, usually with a rapid response time of 1 day or less. Soil moisture content also changes with respect to the reservoir water level, and the area where seepage from the reservoir is a possibility has a relatively high soil moisture content. The similarity of measured seepage rates at the outflow site and the seepage rate estimated by Darcy’s law suggests strong connectivity and high density of the fractures. The estimated seepage rate using a numerical model for the northernmost valley (Zone 1) is approximately 127.2 m³/day in the case of high reservoir water level and 24.3 m³/day in the case of low water level. Continuous monitoring to obtain time series data for water levels, quality, and bedrock displacement is recommended to assess the sustainable stability of this geologic barrier.     

Identification of sources and causes of leakage on a zoned earth dam in northern Taiwan: Hydrological and isotopic evidence

Seepage through an earth dam body must be regulated as a well–planned process, if it is not properly managed, the abnormal seepage may cause dam failure. This study employed stable isotopic and statistical methods to identify the source and cause of an abnormal leakage on the zoned earth dam of the Xin–Shan reservoir located in northern Taiwan. Water samples from the dam area over a 2-a period were collected and analyzed for their stable O and H isotope compositions. In addition, a 4-a period of hydrological data, including rainfall, reservoir level, well level, seepage of filter drainage and leakage, were statistically analyzed with a stepwise multiple regression approach. Both the stable isotopic and hydrological results indicate that the abnormal leakage on the dam shell comes from the filter drainage in the dam. The reason for abnormal leakage is due to unexpected and significant precipitation–sourced water flowing into the dam’s body. The dam filter fails to drain out the incoming water sufficiently, thus generating the abnormal seepage. In addition, the defect in the dam filter may also cause the drainage filter to drain off reservoir seepage inadequately. Therefore, it is suggested that checking the filter function and preventing excessive precipitation–sourced water from flowing into the dam are the two top priorities for the follow-up remedial strategy of the dam.     

蓝洞水库大坝病险综合物探勘查

针对蓝洞水库均质大坝出现散渗等病险,根据区内各介质物理性质及地球物理特征,合理选择了高密度电阻率、探地雷达、瞬态瑞雷波和自然电场4种物探方法进行综合勘查,查明病险的水源来向,为评估坝体的稳定性和加固处理设计提供依据.     

某水库坝基渗透稳定性研究

某拟建高为22 m的混凝土重力坝坐落于第四系冰水堆积层之上。在大坝上下游水头差的作用下,产生库水渗漏。库水的大量漏失,不但可能使大坝蓄水达不到设计高程而影响工程效益,而且,水流的渗透作用还会导致地基岩（土）体的恶化,产生渗透破坏,影响大坝本身的安全。在现场调查基础上,用数值模拟方法评价了该水库在库内设置175 m长铺盖条件下的渗漏问题,计算了水库的渗流量、大坝基底的水力坡度。因其量值较大,必须在渗流出口处采取反滤层等工程措施,给相关部门提供设计依据和决策参考。     

黄河聊城段侧渗分析研究

黄河在山东境内属地上河,常年补给两侧地下水,是沿河地带地下水资源的重要组成部分.依据黄河聊城段东阿县境内的艾山侧渗断面1986～1994年地下水位资料,在分析水文地质条件和地下水流态的基础上,应用水均衡原理分析计算导水系数T,并通过同位素示踪试验得到了验证.利用达西公式计算单侧年侧渗量,建立艾山水位、年径流-侧渗量关系,并与应量平衡法和地下水非稳定流公式计算的成果作了对照分析.     

Turbidity control in downstream of the reservoir: the Nakdong River in Korea

High turbid water in the river has been one of the major concerns to the downstream residence. During heavy local rainfall, high turbid water occurs in many countries located in the Asian monsoon climate region. The Andong and the Imha reservoir, two adjacent multipurpose dams, located in the upstream of the Nakdong River in Korea have suffered from severe turbid water problem. This study applied hydrodynamic water quality model CE-Qual-Riv1 to simulate turbidity propagation in downstream coupled with long-term watershed hydrologic model SWAT to consider contributions of tributaries. The outputs of runoff and suspended sediment in tributaries are incorporated into the input data necessary for the hydrodynamic water quality model. The simulation focused on the joint dam operation to minimize the negative impact of high turbid water in downstream river. Simulated turbidity in downstream shows a good agreement with the observed data, and the approach proposed in this study is applicable for establishing a sound turbid water management in downstream of the reservoir.     

悬托河及其形成条件的初步研究

碳酸盐岩区悬托河谷的水文地质结构比较复杂。当修建水库时,渗漏常是最主要的工程地质问题。作者对悬托河谷的水文地质结构进行了划分,并对悬托河的形成条件进行了探讨,这对选择良好的库坝位置,指导工程地质勘察,评价水库渗漏,合理制定开发方案、工程规模及防渗措施,都具重要意义。     

Evaluation and rehabilitation of dam seepage problems. A case study: Kafrein dam

The intention of this study is to locate the probable sources of the Kafrein dam seepage problem. A methodology known as excitation-response analysis will be considered. Analytical expressions, depicting the groundwater level response in the underlying aquifer as a result of changes in the reservoir water level, were derived from a linearized groundwater flow equation for one-dimensional semi-infinite, isotropic and homogeneous porous media. The results revealed that a large proportion of the seepage water originates from a site at a distance about 1 km from the observation point M1 and streamlines along the existing faults. Emphasis in this work was also placed on controling and mitigating the seepage problem.     

山西太原西山汾河二库的泉域归属及其渗漏量计算

山西省汾河二库是建于汾河中上游的一座大型水库。由于水库处于晋祠兰村泉域交界地带的碳酸盐岩河段,水库蓄水并淹没了天然条件下出流的悬泉寺泉群,造成库区岩溶水文地质条件发生根本性改变,直接影响到泉域岩溶水的水资源评价、开发管理和以泉水复流为目标的生态修复的措施制定。本文针对汾河二库修建后的以下两个问题开展了讨论。第一,利用最新调查与勘探资料分析二库修建对岩溶水文地质条件的影响,并对二库库区的泉域归属问题进行了划定,认为悬泉寺泉水的出流受控于汾河河谷内向西倾斜的下奥陶统区域相对隔水层的阻水作用,汾河二库蓄水水位提高近40 m,天然条件下挟持于晋祠-兰村泉域间相对独立循环的悬泉寺泉域降落漏斗被“充满”,泉水消失,形成对岩溶地下水渗漏反补给,水库渗漏水量通过中奥陶统主要进入晋祠泉域,汾河二库以寺头-下槐间下奥陶统出露的地段为界,下槐泉以上划归晋祠泉域,下槐泉以下则划归兰村泉域;第二,利用二库上游寨上水文站、下游的上兰村水文站资料和二库蓄水水位系列资料,由均衡法建立了二库蓄水水位与渗漏量之间的非线性方程,并据此预测,当二库水位提高至905.7 m时的渗漏量为2.862 m3·s-1,而对兰村泉域岩溶水及山前西张水源地的补给量有限。      

Impact of impoundment on groundwater seepage in the Three Gorges Dam in China based on CFCs and stable isotopes

It is a common concern that the groundwater flow field caused by the Three Gorges Dam changes the regional seismic activity and environment. The changes in the seepage region could be effectively reflected through the analysis of the groundwater age using chlorofluorocarbons (CFC)-based techniques. In this study, the influences of the reservoir water on groundwater and the seepage region boundary of the reservoir were investigated using CFCs, stable isotopes, and water level in groundwater, reservoir water, and spring water during the water storage process of the Three Gorges Reservoir. The results show that the water supplied by the groundwater is older, whereas the water supplied by the reservoir and the springs is younger. With an increase in the water level of the reservoir, the water in well W3, which is located at the vice dam of the head region, becomes older due to the reservoir loading effect, whereas the water in well W4 become younger due to the lateral seepage of reservoir water. This finding indicates that the groundwater seepage regions in wells W3 and W4, which are located at upstream of the reservoir, are all influenced by the Three Gorges Reservoir. In contrast, the sampling points in the northern section of the Xiannvshan fault zone, which is farther from the dam, did not exhibit any direct hydraulic connection between the groundwater and the reservoir water; thus, the reservoir seepage effects may not affect the northern part of the Xiannvshan fault zone. These research results provide important reference data that can be used to analyze the effects of the Three Gorges reservoir storage on the regional environment.     

Role of geological structures in seepage from Lar dam reservoir

The main objective of this paper is to estimate the water seepage from Lar dam reservoir based on a combination of the geological structure study results and identification of the flow conduits in the right bank of the reservoir. From the beginning of impounding the dam in 1980, heavy seepage was observed at two karstic springs, Haraz and Galugah, located about 9 km downstream of the dam. During the first impounding, the discharge of the Haraz spring abruptly increased from 0.5 m³/s to around 5 m³/s. The results of piezometers and dye tests indicate that seepage occurs mainly through the right abutment of the dam where there is a structural wedge between the north dipping North Tiz Kuh and the south dipping Lar Valley faults. F1, F2, and F3 faults are the most important faults in vicinity of the structural wedge. Based on the dye test results, the North Tiz Kuh and F3 faults along which caves No. 1 and 2 are formed are regarded as two isolated conduits for seepage and conveyance into Lar Valley Fault at downstream of Lar dam. After identifying the conduits, water seepage from the Lar dam reservoir has been calculated using finite element method. According to the results of numerical method, when the reservoir water level is at 2485 m a.s.l, the average of water seepage is around 8.51 m³/s (this amount of water is related to the seepage along the Lar Valley Fault). The average discharge of springs downstream of the dam has been used to verify the numerical method. The results show a very close relation between estimated and observed discharge.     

库水位骤降后面板缺陷坝体渗漏量和坝坡稳定性分析

为研究库水位变动情况下面板不同缺陷的面板堆石坝渗透稳定特性,利用著名岩土分析软件Geo-studio的Seep/w与Slope/w模块,以浙江省临海市西部括苍镇境内某面板堆石坝为例,对不同土工膜缺陷及库水位变动工况的组合进行了渗流特性及稳定性的数值模拟分析,得到了浸润线,渗漏量及稳定性系数的变化曲线,计算结果表明:(1)面板一旦发生缺陷,静库水位下坝体的浸润线有一个明显的抬升,缺陷尺寸越大,浸润线高程越高,但是差异不大。库水位高程越高,静库水位下坝体内部的浸润线高程也就越高;(2)库水位水平越高,缺陷尺寸越大,坝体渗漏量也就越大;(3)库水位骤降下面板坝内部浸润线呈现先疏后密的规律,库水位下降速率越大,上游坝体浸润线疏的部分则越疏。在库水位骤降经过面板坝缺陷高程时,有一个浸润线突降的过程;(4)从整体上看,上游坝坡的稳定性系数要大于下游坝坡的稳定性系数;静库水位下,库水位水平越高,上游坝坡稳定性系数越大,而下游坝坡稳定性系数则越小,缺陷位置越高,稳定性系数越低;库水位骤降情况下上游坝坡稳定性系数随库水位下降呈现先下降后上升的趋势,下游坝坡则呈现一直上升的规律,一旦面板发生缺陷,稳定性系数较完整面板来说有一个较大幅度的下降,面板缺陷尺寸越大,稳定性系数整体上越小。