某河床式水电站消力池优化试验研究

通过对某河床式水电站进行水工模型实验,提出了对原设计消力池的改进优化方案。试验表明,原设计方案的消力池段在通过设计流量50年一遇的洪水3 580m3/s时,池内不能形成水跃,原设计方案的消力池深和消力池长均不能满足过流条件。优化设计中包括加高尾坎,加深消力池和将原消力池作为过渡段,并紧邻新建一个消力池5个备选方案。优化后的试验结果表明,消力池内流态明显改善,水跃长度减小,跃后水深降低,下游冲刷深度减小,消能率提高。最终考虑采用将原消力池作为过渡段,新修消力池的方案,可以减少开挖量,降低工程造价,试验结果可为优化工程设计及其他同类工程优化消力池提供参考。     

铧尖子水库消力池修改方案试验研究

铧尖子水库是辽宁省本溪市的重要病险水库,除险加固刻不容缓。在借鉴相关理论研究成果的基础上,结合模型试验成果对铧尖子水库消力池设计方案进行优化设计,并提出6组优化设计方案。模型实验结果显示:消力池在2%设计洪水条件下,修改方案6能够达到比较理想的消能效果,对下游海漫和堤岸基本没有不利影响。因此,采用此方案作为消力池的最终设计方案。     

小石峡水电站溢洪道消能工优化试验

通过新疆维吾尔自治区库马拉克河小石峡水电站溢洪道水力学模型试验,对其原设计方案的消能工结构形式进行了优化。试验表明,消力池段在通过设计流量30年一遇洪水1 856.20m3/s时,池内不能形成完整水跃,水跃前后波动剧烈,水流大量溢出,原设计方案的边墙高度、池长均不能满足过流要求。提出采用减小消力池池深、设置分流趾墩-消力墩-低消能坎的综合式消力池代替原设计方案的常规消力池的修改方案,在设计流量下进行泄水试验,试验结果表明,在分流趾墩、消力墩、低消能坎的联合作用下,消力池内形成强迫水跃,流态明显改善,水跃长度减小,跃后水深降低,消能率提高。采用分流趾墩-消力墩-低消能坎的综合式消力池可有效缩短消力池池长,降低边墙高度,节省工程造价,试验结果可为优化工程设计及其他同类工程优化消力池提供参考。     

消力池内悬栅辅助消能工优化试验

针对新疆迪那河五一水库溢洪洞消力池原设计方案不能满足正常宣泄洪水的问题,对消力池内梯形墩和T形墩的位置、数量和尾坎高度等进行调整,设计了17种消力池修改方案,并采用悬栅与梯形墩联合运用的综合式消力池,通过对悬栅优化方案的比选和悬栅高度的合理性验证,最终确定了溢洪洞消力池悬栅消能工的最佳方案进行优化。试验结果表明:悬栅消能工的设置解决了原设计方案水流溢出池外、不能形成淹没水跃的问题;消力池池长由原设计方案的83 m缩短至70 m,避免了工程投资的增加。     

肯斯瓦特水利枢纽溢洪道流场的数值模拟研究

对新疆肯斯瓦特溢洪道及消力池建立了三维模型,采用结构网格和非结构网格结合的方式对模型进行了网格划分,利用Realizable k-ε紊流模型和VOF模型相结合的数值方法对其三维流场进行了数值模拟,结果表明,原设计方案下水流不稳定,消力池内消能效果较差。为此提出在消力池内增加T形墩的修改方案,增设T形墩后消力池内水流对称,消能效果显著提高,可达到工程设计要求。由此可见,数值模拟方法能够作为试验的补充方法,为工程实际应用提供依据。     

曲线型消力池消能特性及优化设计模型试验研究

底流消能工消力池平面布置大多采用等宽直线型,但在弯曲河段采用直线型消力池将大大增加岸坡开挖工程量。通过水工模型试验,研究了德党河水库曲线型消力池内的水流特性及存在的问题,对设计方案进行优化,并进行了模型实验,实验表明采用跌坎式曲线型消力池能有效解决折坡段容易出现的空蚀现象和消力池内水流折冲明显等问题,且消能效果明显。     

基于力学模型试验的总干渠东关隧洞出口段的设计优化

对于总干渠东关隧洞出口段施工段,通过应用水工模型试验,首先需要对原设计方案出口段消能进行验证,其次,进一步对原设计方案修改、调整及优化。根据原设计方案的试验结果,并由设计部门提出修改意见,完成模型修改。文章对复核隧洞出口段的泄流能力、消力池水流流态、消力池消能效果进行力学模型试验,结合实际情况对力学模型试验进行修改,对总干渠东关隧洞出口段设计方案进行优化。     

阿尔塔什水利枢纽工程底流消力池水力特性试验研究

为深入研究消力池内水力特性的分布规律,以新疆阿尔塔什水利枢纽1#深孔放空排沙洞为研究对象,通过1∶37.89水工模型对工程原设计方案以及体型优化方案中消力池内水流流态、临底流速以及脉动压强进行了试验对比分析。结果表明,随着入池水流流量的增大,临底流速及脉动压强均有增大的趋势;设置跌坎后临底流速减小,但是底板脉动压强有所增大;降低消力池底板高程可以改善水力特性。最后,试验对工程最终所选的消力池体型提出了建议。     

高岭拦河闸重建工程消能试验研究

通过对高岭拦河闸重建工程的消能试验,提出了将拦河闸消力池按2种形式分区布置的方案,利用该方案中池底高程相对较低的中间单元消力池承担拦河闸的初始泄流任务,较好地解决了在设计方案布置泄放小流量时存在的消力池消能不足的问题。该方案不仅满足了拦河闸的消能要求,又节省了工程投资,可为同类工程的设计提供借鉴。     

江巷水库枢纽溢洪道总体布置研究

江巷水库溢洪道设计方案采用两级消力池型式,本文通过试验比较,详细研究了溢洪道一级消力池与二级消力池的消能效果,认为一级消力池较二级消力池更适合该枢纽。同时通过增加消力墩、降低消力池底高程和减小消力池边墙扩散角等措施改善消力池的消能效果,使溢洪道的总体布置满足设计要求。     

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.     

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。     

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.     

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.     

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。     

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。     

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.     

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。     

小湾水库大坝防渗面板及其裂缝的加固处理

小湾水库大坝防渗面板整体抗渗性能差,且存在多条裂缝,通过对面板钢丝网喷涂丙乳砂浆加固处理及其裂缝修补,大坝渗漏量明显减少,且左岸上灌浆廊道内及大坝下游坝面92～93 m高程下廊道入口处原有小股射流全部消失.