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JP水电站施工过程中,厂房已浇筑的结构发现多条裂缝。经对裂缝产生的原因及裂缝对厂房安全性影响的分析,针对不同部位裂缝提出相应的处理方案。 相似文献
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廖坊水利枢纽工程电站厂房为河床式, 为枢纽挡水建筑物。施工期间, 在厂房施工围堰拆除挡水之后, 发现水
机廊道底板上有裂缝并有渗水冒出。通过底板结构强度复核并结合施工过程中的温度应力特征, 对裂缝成因和危
害性进行了分析, 并提出相应的裂缝处理方案。经处理后, 有效消除了水机廊道底板渗水现象, 确保电站厂房的正
常运行。研究成果对类似工程有一定的参考价值。 相似文献
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大体积混凝土的各种裂缝防不胜防,裂缝虽小,但对建筑物的危害却很大。结合庙子头水电站工程厂房混凝土裂缝处理实践,分析产生裂缝的原因,提出有效的处理措施,以确保电站安全运行。 相似文献
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大体积混凝土裂缝成因分析及其防治措施探讨 总被引:1,自引:0,他引:1
该文分析了大体积混凝土材料型裂缝产生的原因,概括介绍了该裂缝的防治方法。并以黄塘甲水电站厂房裂缝处理为例,具体说明大体积混凝土裂缝的防治措施。 相似文献
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麒麟寺水电站在5.12地震后,坝体出现裂缝。水库蓄水时,廊道及厂房出现不同程度的渗水。为确保电站安全运行,需要对坝体裂缝进行处理。通过对裂缝进行化学灌浆处理,取得了很好的效果。 相似文献
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雅砻江锦屏一级水电站地下发电厂房地应力高,f13、f14、f18断层贯通三大洞室(主厂房、主变室、调压室)。受f18断层及煌斑岩脉影响,第1副厂房与第2副厂房之间的上下层联系洞内裂缝发育,监测断层围岩变化对主厂房与主变室之间岩墙稳定性的影响尤为重要。采用石墨杆收敛计对地下发电厂房上下层联系洞进行监测。监测结果显示,第1副厂房与第2副厂房之间的上下层联系洞裂缝主要是由应力持续卸荷引起的深部劈裂性开合裂缝。由于采取及时有效的支护和回填处理,高边墙之间的岩柱变形无异常。实践表明,石墨杆收敛计是监测洞室深部裂缝的有效措施。 相似文献
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广东省潮州供水枢纽西溪厂房存在多处渗水裂缝或渗水点,导致设备层和廊道层工作环境潮湿,运行条件差,影响厂房安全。通过采用化学灌浆补强防渗处理的方法,有效解决了厂房渗水问题,排除了安全隐患。该文详细介绍了厂房渗漏处理的关键技术,对同类工程有较好的参考应用价值。 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