构皮滩水电站导流隧洞设计概述

构皮滩水电站是乌江上设计最大的水电站,其施工导流采用3条导流隧洞,具体布置为左岸2条,进口高程分别为430,450m;右岸1条,进口高程为430m。3条导流隧洞过流断面均为15 6m×17 7m的马蹄形。在地质复杂的岩溶地区实施大洞径的导流隧洞,对设计提出了更高的要求,文章就构皮滩水电站导流隧洞的布置、结构设计及成洞条件等进行了详细的阐述。     

滩坑水电站的施工导流设计

滩坑水电站施工导流设计分为4个导流时段,其中工程第一阶段导流采用围堰挡水,来水由1号导流隧洞下泄;第二阶段导流采用围堰、大坝过水,来水由1号导流隧洞与基坑联合下泄;第三阶段导流采用枯水期由围堰挡水,来水由1号导流隧洞下泄,汛期由大坝临时断面挡水,来水由1号和2号导流隧洞联合下泄;第四阶段导流采用大坝挡水,来水由2号导流洞下泄.第一阶段导流标准按10年一遇洪水设计,相应设计洪水流量2 420m3/s;第二阶段围堰及大坝过流设计标准按全年20年一遇洪水设计,流量10 400m3/s.左岸布置了2条导流隧洞,进口高程分别为34.5m、65m.     

构皮滩水电站导流规划与设计

构皮滩水电站施工导流分为3个阶段:初期导流、中期导流和后期导流.工程初期导流采用RCC围堰挡水、隧洞泄流的全年导流方式;中、后期采用坝体临时挡水,坝身导流底孔、放空孔、泄洪深孔、表孔及泄洪洞相结合的全年导流方式.初期导流时,利用上游已建的乌江渡水库预留防洪库容,可有效地减小导流隧洞和上、下游围堰的规模.介绍了构皮滩水电站导流规划、导流标准、施工导流程序及主要导流建筑物设计.     

寺坪水利枢纽施工导流设计

寺坪水利枢纽是汉江中游右岸支流南河上段开发的重要梯级。大坝拟选用粘土斜心墙坝。根据坝址地形地质及水文条件，施工导流方案选定为枯水期采用1条隧洞导流，汛前抢筑大坝临时挡水断面，汛期由大坝临时断面挡水，隧洞导流，大坝全年施工。阐述了导流建筑物的布置与设计，施工导流方式与程序，截流设计等。可供其它工程参考与借鉴。     

大盈江一级水电站工程施工导流设计

大盈江一级水电站是大盈江流域梯级开发的龙头电站,导流工程处于虎跳石省级风景区,流量大,环保要求高,施工场地狭窄,施工难度大.根据坝址处地形、地质、水文条件和水工建筑物布置.大坝施工拟采用枯水期围堰一次断流、右岸隧洞过流的导流方式.施工期度汛方式为:枯水期采用围堰挡水,导流隧洞过流,汛期采用坝体挡水度汛,导流隧洞、冲沙底孔和未完建表孔泄洪.度汛坝体高程为785.0 m.     

乌东德水电站导流规划与设计

乌东德水电站施工分初期导流、中期导流和后期导流。初期导流采用隧洞泄流、土石围堰全年挡水导流方式;中、后期采用导流隧洞、坝体中孔、表孔和泄洪洞联合泄流,坝体临时断面全年挡水导流方式。受地质条件影响,两岸导流洞靠山侧布置,导致洞线长、规模大,且由于洪峰来量大,导流洞断面也较大。简要介绍了乌东德水电站导流规划和导流建筑物布置、导流标准、导流程序及导流建筑物设计等,可供类似具有复杂导流条件的水电站施工参考。     

渫水皂市水利枢纽施工导流设计

漂水皂市水利枢纽采用河床一次断流、右岸隧洞导流的施工导流方式。施工导流时间为2004年10月～2007年9月，分为3个阶段：截流至坝体临时挡水度汛前；坝体临时挡水度汛至导流隧洞下闸封堵；导流隧洞下闸封堵至工程永久泄洪建筑物具备设计泄洪能力前。具体介绍了施工导流标准、施工导流程序、主要导流建筑物设计和导流隧洞封堵技术等。     

构皮滩水电站导流隧洞设计

构皮滩水电站是乌江上最大的水电站,采用围堰全年挡水,导流隧洞泄流的施工导流方案.导流隧洞共有3条,按左2右1分两岸布置,过流断面均为15.6 m×17.7 m的马蹄形.构皮滩导流隧洞沿线地质条件复杂,既存在众多的地下岩溶系统,同时每条洞又要穿过长达100多米的韩家店软岩段.在地质条件如此复杂的岩溶地区实施大洞径的导流隧洞的设计和施工,对设计思想和施工技术提出了更高的要求.介绍了构皮滩导流隧洞的设计和施工.     

满拉水利枢纽工程导截流设计与施工

1　导流方式及拦洪度汛方案1.1　导流方式满拉水利枢纽采用一次断流、隧洞导流的导流方式 ,导流洞后半部分与泄洪洞结合 ,进口高程 4190 .0 0 m ,出口高程 4184.5 0 m,隧洞总长 6 48.774m,其中专设导流洞长2 92 .6 m ,断面尺寸为 7.5 m× 6 .3m(宽×高 ) ,城门洞型 ,与泄洪洞结合部分长 35 6 .174m.大坝上、下游围堰采用土石围堰 ,设计挡水标准采用大汛 10年重现期流量 199m3/ s.1.2　拦洪度汛方案截流安排在 1996年汛后 ,截流后的第一年即 1997年大汛 ,导流隧洞过流 ,按 10年重现期洪水流量 199m3/ s计算 ,坝前水位 4197.3m ,大坝基坑在围…     

糯扎渡水电站工程施工导流设计概述

糯扎渡水电站工程具有坝体高、库容大、导流流量大、蓄水历时长等特点，因此导流方式、导流标准等的研究是导流设计的难点和重点。通过分析研究，初期导流采用河床一次断流、土石围堰挡水、隧洞泄流、主体工程全面施工的方式；中、后期导流采用坝体临时断面挡水、导流洞泄流(或泄洪洞和溢洪道临时断面泄流)方式。糯扎渡工程施工导流设计为工程施工的顺利实施提供了必要保证。     

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.     

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.     

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.     

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.