大吊点距卷扬式启闭机同步控制的设计及应用

由于卷扬式启闭机所特有的优点,使其在水利水电工程中得到非常广泛的应用,阐述了岩石岭除险加固工程水库泄洪闸30 m下沉式工作闸门2×800 kN大吊点距卷扬式启闭机由变频调速同步控制技术的应用。     

反调节水库泄洪闸液压启闭机原理及故障处理

小浪底西霞院反调节水库2006年截流蓄水以来,顺利参与了2年黄河调水调沙工作,设备运行状况良好,其中泄洪闸弧门启闭机运行较频繁,闸门启闭时出现爬行现象、速度不均问题。详细介绍了泄洪闸液压启闭机液原理及故障,提出了处理故障的具体措施。     

大中型水库调度自动化应用系统

随着全省水利信息网二期工程的建设,要求对重点工程的动态图像进行传输,这对水库本身的调度自动化提出了更高的要求。要求水库必须建立自身的集中调度控制系统。1 监控系统 监控系统采用了开放、分层分布式计算机控制技术,分为三级即现地控制级、主控级和总控制级。现地控制级设于溢洪闸和放水洞的每台启闭机的机旁     

履行监督职责 确保工程质量

龙门水库除险加固工程自2002年9月17日开工建设以来,已相继开工的工程有主副坝输水洞加固工程、泄洪闸土石方工程、十八坡副坝土石方工程、泄洪闸主体工程、泄洪闸闸门及启闭机制造工程5个单位工程。截至目前,主副坝输水洞加固工程已完建验收,其余4个工程也已完成大部。从已完工程的情况看,工程质量达到了合同规定的等级要求。     

小浪底反调节水库泄洪闸弧门电气控制系统的组成及特点

主要介绍小浪底反调节水库泄洪闸弧门电气控制系统的配置、功能和特点.由于采用可编程逻辑控制器(PLC)和BTL5-E17系列位移传感器等技术,小浪底反调节水库泄洪闸弧门控制系统具有数据采集精度可靠、双缸同步误差小、纠偏灵敏等优点,为闸门的远程操控提供了有力保证.     

黄河沙坡头水利枢纽工程泄洪闸大型弧门及液压启闭机布置和设计

沙坡头水利枢纽工程泄洪闸是本工程重要的泄洪建筑物，担负着工程90％以上的泄洪量，泄洪闸的布置优劣，产品闸门设计的刚度、强度及稳定性，启闭机选型是否合理，以及启闭机的同步等均关系着工程的安全性。为此，着重介绍泄洪系统金属结构的布置及金属结构设备的设计特点。     

泄洪闸应急控制系统在深溪沟电站的应用

深溪沟电站水库库容较小,在全厂失电、机组停机或者上游来水量突增等紧急情况下,水库水位会快速上涨,危及电站大坝及厂房设备的安全,同时会造成下游供水中断,影响下游企业的供水。为满足电站"无人值班,少人值守"的要求,保证在水库水位过高时泄洪闸门可自动开启至适合高度进行泄洪,降低水库水位,设计泄洪闸应急控制系统。重点介绍了泄洪闸应急控制系统在深溪沟电站的成功应用。     

张掖市黑河草滩庄水闸枢纽除险加固措施

文章简述了黑河草滩庄水闸枢纽除险加固的建设背景;水闸存在闸前库区泥沙淤积,泄洪闸闸门启闭困难;水闸右侧土坝、导水裹锥坝坡局部冲刷坍塌;泄洪闸下游护坦冲刷,闸前左岸防护堤冲毁;进水闸、泄洪闸闸门启闭机及电气、控制、通讯、检修设备老化,泄洪闸闸底板冲刷剥蚀、锈蚀等问题;提出了在水闸上游左右侧布置导墙;修建左岸堤岸护坡;在龙渠二级电站末端设置进水闸、泄冲闸、引水渠、挑水丁坝;加固泄冲闸启闭机室上下游主梁及闸底板;加固水闸右侧土坝、导水裹锥及下游齿墙、翼墙;更换加固进水闸、泄洪闸闸门、启闭机及电气、通讯设备;增设水闸枢纽运行管理设施等除险加固措施.     

老石坎水库除险加固设计实践

针对老石坎水库存在坝体填筑质量差、心墙防渗性能差、两岸存在绕坝渗漏、正常溢洪道泄洪闸左岸边墩与大坝接合部位存在绕渗、闸门和启闭机均存在较严重的安全隐患等问题,采用心墙套井回填粘土、倒挂井混凝土防渗墙、帷幕灌浆及非常溢洪道改建加固等一系列措施,消除了隐患,提高了大坝的安全度及水库运行调度的灵活性、可靠性.     

泄洪闸应急控制系统在枕头坝水电站的应用

枕头坝水电站为确保泄洪闸运行的稳定性和供电的可靠性配置了泄洪闸应急控制系统,其作用、组成、控制逻辑及实现方式为:根据库水位实现泄洪闸的应急控制,防止水库水位超过警戒线水漫大坝;根据全站突然甩负荷情况实现自动开启泄洪闸门;大坝电源消失及时自动启动柴油发电机,确保大坝5孔闸门电源应急供给。     

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。     

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.     

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.     

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。     

Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system, configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants of dry ash utilization and the advantages of producing of size-separated particles are considered. __________ Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008).     

The flood pulse advantage and the restoration of river-floodplain systems

The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed.     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Short communication. Pipelines as a refuge for freshwater snails

In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.