首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
揭新 《水力发电》2003,29(5):54-56,73
2002年,对三峡工程永久船闸北线一二级船闸地面工程结构缝渗漏情况进行了普查和处理。根据具体情况,主要采取了以下处理措施:闸底板非过流面采取缝口切槽 嵌填SR—2塑性止水 SR防渗盖片 混凝土防护扳的处理方案,过流面采取止水检查槽分段堵塞 灌注LW材料的处理方案;闸边墙缝面渗水采取缝口切槽 嵌填聚硫密封胶,并与底板I型表止水连接的处理方案,对于渗漏量大的采取缝口切槽 嵌填聚硫密封胶 止水检查槽分段灌注LW材料的方案。2002年9月,永久船闸进行有水调试,经检验,渗漏处理效果良好。  相似文献   

2.
针对大坝运行期水下横缝止水渗漏处理问题,研究提出了利用置换式灌浆法对止水检查槽进行封堵的处理方法,并系统地介绍了该方法的工作原理、施工条件和工艺过程,以及在三峡大坝中的实际应用情况,对这一方法的特点和适用范围进行了说明,为大坝横缝止水渗漏问题的解决提供了新的途径和手段。  相似文献   

3.
三峡双线五级船闸闸室及闸首均为分离式的不透水结构,结构缝内止水系统的防渗效果是决定船闸安全运行的重要方面,竣工验收前对止水系统进行了全面检查处理。主要对压水检查、渗漏处理方案决策及实施情况作全面闸述。  相似文献   

4.
水工混凝土迎水面渗漏主要有止水结构渗漏,抗渗标号低于设计标准,冷缝渗漏,外漏蜂窝,麻面渗漏。文章提出可用补灌沥青、钻孔灌浆、补做止水设施采取补做坝面止水结构和加镶铜片以及建筑物顶上做截水墙等项措施防止渗漏。  相似文献   

5.
面板坝接缝不锈钢波纹状止水片试验研究   总被引:2,自引:0,他引:2  
1的自混凝土面板堆石坝(简称面板坝)具有工期短、投资省、施工方便、安全可靠等诸多优点,因而被世界各国广泛采用,目前的发展趋势是建200~300m高坝.面板坝在水库蓄水过程中,周边缝的止水结构要承受趾板和面板间相对较大的三向变位,容易遭到破坏,形成面板坝防渗体结构中的主渗漏通道.面板坝周边缝一般采用三道止水结构,即由底部钢片止水,中间塑料或橡胶止水及顶部加盖保护的柔性填料组成,这种止水结构已在国内外一些面板坝工程中得到应用.面板坝三道止水结构所存在的不足之处,文献【1]做了详细的分析.铜片作为最基本的止水…  相似文献   

6.
禹门黄河提水工程二干渠从1991年开始施工至今已完成渡槽13座。渡槽均为12.5m3/s~14m3/s的大流量U型薄壳结构,跨度10m,槽体宽3.6m、深2.8m,槽身厚度13cm。两跨接头处外面为梯形,内面为弧形。两跨之间的伸缩缝为3cm。渡槽两跨之间的止水缝采用纤维布聚氯乙烯胶泥进行施工,止水达到了设计标准,几年来渡槽多次上水均无漏水现象。槽身止水缝结构见图1。1止水缝施工的准备工作为了适应复杂的建筑形式,加强涂料止水的整体性,特别是考虑到悬空的槽体两跨之间止水缝因伸缩量较大,按设计要求选用…  相似文献   

7.
为了防止闸门渗漏水,就应有一套有效的闸门止水系统,保证各部位止水装置与止水座面接触的连续性和严密性,防止水从止水橡皮与闸门门叶之间的接触面渗漏或从止水橡皮与闸门门槽埋件之间的接触面渗漏。为此,应控制闸门门叶的制造质量、闸门止水系统的制造安装质量和闸门门槽埋件的制造安装质量。  相似文献   

8.
面板坝靠薄层混凝土面板作为主要防渗体,其接缝的止水就显得尤为重要,如果这些接缝发生大量渗漏,将会对工程的安全性和经济性产生严重影响。为提高面板坝周边缝的止水性能,分别从结构设计、止水原理及结构和材料不足等方面对面板坝周边缝几种典型止水结构型式进行对比分析,结果表明:高面板坝周边缝新型止水结构设计型式,既保留了各自结构的长处,又弥补了各自的不足,同时具有创新的特点。  相似文献   

9.
张新军  南海霞 《人民长江》1999,30(10):28-28,31
葛洲坝3号船闸自1981年投入运行以来,尚未进行过大的修补,直至1996年经检查发现;基础排水廊道淤积严重渗漏量大,部分结构有明显的挤压破坏,特别是闸室底板两条纵缝及分流口支廊道部位的渗漏量为最大。对渗漏的处理,采用骑缝凿槽后铺填GS胶进行表面止水是十分有效的。CS胶为改良聚基甲酸酯,是双组份反应型流状或膏状密封材料使用寿命长。该材料固化后生成不溶于水的网状构造高分子橡胶胶体,具有良好的弹性、粘结  相似文献   

10.
为研究混凝土面板堆石坝垂直缝接缝止水劣化引起的渗漏量和渗透坡降的变化规律,以某面板堆石坝为例,采用有限元计算方法,模拟了面板左岸垂直缝、面板中间垂直缝、面板中间垂直缝不同高程分别发生止水劣化过程中的渗流,计算了不同工况下通过面板渗漏量、量水堰渗漏量测值、浸润面分布,分析渗透坡降和量水堰测值的关系。计算结果表明,量水堰测值能够反映出面板垂直缝止水劣化程度及垫层区渗透坡降是否超出允许值;随面板止水劣化,面板中间垂直缝较面板左岸垂直缝引起的渗漏量更大、浸润线上升更为明显;面板中间垂直缝随高程降低,引起的渗漏量增加、浸润线上升更为明显。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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。  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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。  相似文献   

18.
簸箕李引黄灌区水沙分布及优化调度的经验   总被引:1,自引:0,他引:1  
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。  相似文献   

19.
小湾水库大坝防渗面板及其裂缝的加固处理   总被引:1,自引:0,他引:1  
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.  相似文献   

20.
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.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号