塑性混凝土防渗墙在龙湾水库除险加固工程中的应用

黑山县龙湾水库采用塑性混凝土地下防渗墙对坝基渗漏进行处理,收到了较好的效果。文章介绍了施工的主要方法和工序,可供中小型水库除险加固工程参考。     

王祥水库坝基渗漏原因及处理措施

莒南县王祥水库坝基渗漏,年渗漏量约占兴利库容的6%,在小型水库除险加固过程中,通过分析水库坝址处的地层岩性、坝基水文地质条件,找出水库坝基渗漏的原因,采用坝基帷幕灌浆处理措施,使坝基渗漏问题彻底解决。     

桃云水库工程坝基的渗漏评价及防渗处理设计

桃云水库已运行20多年,由于坝基清基不彻底,坝基岩石裂隙发育,正常蓄水位运行后出现渗漏。经综合比较采用坝基帷幕灌浆防渗方案,防渗处理后坝后再没有出现渗漏点,渗流得到有效控制。主要阐述了桃云水库工程坝基的渗漏现状及防渗处理设计。     

帷幕灌浆技术在水库除险加固工程中的运用实例

在病险水库的除险加固施工中,帷幕灌浆技术是处理坝基以及坝肩渗漏的主要措施,运用帷幕灌浆技术可以有效的防止坝基渗漏、降低渗透水对坝基的扬压力,保证坝基以及坝肩的渗透稳定。思南县关田沟水库属小（2）型水库,由于渗透等原因,使灌溉面积大减。文章阐述了该水库除险加固的主要部件。重点叙述了帷幕灌浆技术在对坝基渗透的治理。     

贵州大茅坡水库坝基大流量渗漏处理

针对强岩溶发育地区筑坝建库中坝基渗漏的问题,笔者结合大茅坡水库在试蓄水过程中,面板堆石坝坝基由于岩溶发育出现的大流量渗漏,分析了坝基渗漏的原因,并根据渗漏检测试验结果制定了补强帷幕灌浆的防渗处理方案。灌浆实施后的运行监测结果表明,水库运行情况良好,未发现异常的坝基渗漏,说明渗漏处理效果较好。该大流量渗漏处理的思路为类似问题的处理及类似工程的设计施工提供借鉴和参考。     

尖茶溪水库大坝渗漏现状及防渗处理措施研究

尖茶溪水库运行30多年来,水库存在坝体、坝肩与坝体接触带、坝基及绕坝渗漏。为提高坝体和坝基、坝肩抗渗漏能力,对大坝及两坝肩采用土工膜防渗处理。土工膜具有防渗效果好、耐久性高以及施工方便的特点,在水库除险加固中得到了非常广泛的运用。文章主要阐述了尖茶溪水库大坝渗漏现状以及土工膜防渗处理施工技术。     

坝基深层渗漏通道处理施工方案

坝基渗漏是由于水库蓄水后上下游水头差,使水库的水沿孔隙、裂隙、溶洞、断层等通道向下游渗漏.渗漏降低了水库的经济效益、增大了坝底的扬压力,还可能引起坝基岩体潜蚀,导致坝体失稳,引起安全事故.渗漏处理一般采用防渗墙、帷幕灌浆等方法进行处理,但针对埋藏深、断面大的渗漏通道处理,尚无成熟的施工方法.以块泽河电站坝基渗漏通道处理为例,对其施工过程、方法和要点进行解析.     

浅析双山水库大坝渗漏原因及防渗措施

通过对双山水库大坝进行渗漏分析，认为水库渗漏原因主要是施工时对坝基处理不彻底引起。经过多个方案比较，提出较合理的处理措施。     

水库工程坝体及坝基防渗问题

近年来我国针对存在病险的水库,提出《全国病险水库除险加固专项规划》方案,并对水库工程坝体、坝基的渗漏问题进行加固。对于中小型水库的防渗处理,需要根据区域的地质状况、水库大坝渗漏情况,选择合适方案来完成坝体、坝基的防渗加固。文章主要探讨汝州市安沟水库工程坝体及坝基防渗问题,结合工程实际情况,提出水库坝体及坝基防渗方案。     

白河水库工程中坝基渗漏类型及处理技术

文章针对白河水库工程的坝基渗漏类型进行分析,同时提出了坝基渗漏的处理技术。     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

Serial discontinuities in a Rocky mountain river. I. Distribution and abundance of plecoptera

Samples were taken year-round at eleven sites along the altitudinal profile (2900-1400 m a.s.l.) of the Gunnison River, a 329 km tributary of the Colorado River, to document the distribution of the Plecoptera and to evaluate responses to hypolimnial-release dams in the headwaters and middle reaches. Twenty-two species were present, with the greatest species richness occurring in an unregulated segment upstream of the middle reach dams; average nymphal biomass over the study period (175 organisms, 395 mg dry mass m^?2) was also greatest in this segment. Only four species (58 organisms, 48 mg m^?2) were present in the tailwaters of the headwater dam and values were greatly reduced (nine species; 35 organisms, 180 mg m^?2) below the middle reach dams. The stonefly community recovered ca. 80 km downstream from the last dam (15 species; 244 organisms, 250 mg m^?2), apparently in response to natural resetting of environmental conditions corresponding to those above the middle reach dams. At the most downstream site (11) only four species (four organisms, 16 mg m^?2) were present. The observed distributional pattern is a classic serial discontinuity in response to hypolimnial stream regulation in a temperate latitude river.     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Impacts of Microcystis on algal biodiversity and use of new technology to remove Microcystis and dissolved nutrients

Cyanobacteria often dominate eutrophic lakes, outcompeting green algae that are required by fish and zooplankton. This study was undertaken to ascertain the impact of the cyanobacterium, Microcystis, on algal biodiversity. Under laboratory conditions, we found that the presence of Microcystis decreased phyla richness by 58%, phyla evenness by 47%, genera richness by 66% and genera evenness by 51%. Analysis by mixed anova s demonstrated a significant interaction between treatment and time and confirmed a significant reduction in richness and evenness of phyla and genera. We also conducted a phosphate restriction assay on the algae in Mason Lake (Irvine, CA, USA) and found that the threshold needed for algal growth there was 0.02 mg L^?1 PO₄. A pilot study was then conducted to test the effectiveness of the Blue Pro? water treatment facility in removal of this colonial organism from Mason Lake, in addition to removal of dissolved nutrients required for its growth. We measured a 97% reduction in Microcystis cells, a 72% reduction in chlorophyll‐a, and a 96% reduction in phosphate after just one 10 min cycle through the unit. Our study demonstrated that removal of Microcystis colonies may allow green algae to increase in numbers. This may improve algal biodiversity, which will benefit zooplankton and fishes.     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

簸箕李引黄灌区水沙分布及优化调度的经验

灌区利用水沙观测所取得的资料和试验数据，运用水沙运动力学理论，总结分析和揭示了灌区水沙分布的规律和特点。在此基础上，结合灌区的实际运行情况，围绕减少骨干渠道的淤积进行探讨、研究，进而，优化水沙调度方案。该方案实施后，骨干渠道减旅伴效果明显，取得了成功的经验。