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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。 相似文献
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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。 相似文献
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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。 相似文献
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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。 相似文献
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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。 相似文献
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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。 相似文献
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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. 相似文献
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《河南水利与南水北调》2018,(12)
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。 相似文献
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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
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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
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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
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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. 相似文献
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V. K. Konovalov O. V. Yashkin V. V. Ermakov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2008,42(2):105-109
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.
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Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008). 相似文献
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Peter B. Bayley 《河流研究与利用》1991,6(2):75-86
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. 相似文献