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盾构隧道接缝防水设计探讨 总被引:5,自引:0,他引:5
依据交联橡胶的统计理论,讨论了弹性密封防水材料的非线性应力、应变特性。由材质硬度与杨氏弹性模量的经验公式及静态密封原理,结合相关工程实践经验,提出了防水材料配方硬度及断面型式的设计思想与具体方法,并进行了抗水压模拟试验。提出了评价防水材料耐久性的方法。 相似文献
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在江苏省铜山矿区400 m深复杂地层钻探孔时,破碎、掉块、漏失、水化膨胀、坍塌等现象经常发生,特别是煤系地层遇水很快膨胀、坍塌,造成憋泵而无法钻进。结合该地区地层特点,提出采用SH植物胶冲洗液来解决钻进中的难题,即针对不同地层配制了不同配方的SH植物胶冲洗液加以防护。应用实践表明,SH植物胶冲洗液具有较强抑制和强降滤失能力,有优良的堵漏性能和很强的携屑悬浮岩粉能力,抗剪切稀释能力较强,润滑减阻减振效果明显。 相似文献
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郭志奎 《水科学与工程技术》2001,(4):39-40
建筑物渗漏是工程界,特别是水利工程的一大难题,被称为建筑顽症。据有关资料统计,国家每年用于防渗、防水工程维修的费用就高达10~20亿元之巨。造成建筑物渗漏的原因很多,涉及到材料、设计、施工、运用等各个方面,其中防水材料性能不佳是导致渗漏的最主要的原因。因此加快建筑防渗、防水材料的研发十分重要,而且前景广阔。1防水防渗材料的分类国内外经常使用的防水材料主要分为两大类:柔性防水材料和刚性防水材料。1.1柔性防水材料柔性防水材料又分为卷材和防水涂料两类。1卷材:常用的卷材有沥青质和高聚物改性沥青质… 相似文献
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《水利与建筑工程学报》1996,(1)
兰州新型防水材料厂产品简介兰州新型防水材料厂是西北首家研制生产新型防水材料的骨干企业,又是中国建筑防水材料工业协会、中国建筑防水材料公司推荐的全国主要生产厂家之一。“沙兰牌”改性沥青玻璃布油毡荣获一九九四年国家金奖、首届中国丝绸之路节指定产品、全国渠... 相似文献
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钟山渡槽为双曲拱支承结构,槽身为钢筋混凝土,底板为拼装式微弯板。渡槽于1975年开工,1978年上半年开始通水运行。由于运行时间较长,工程老化严重,槽身存在不同程度的纵、横向裂缝。2001年经过多方案的比较、选择化学防水材料SR塑性止水材料、HK—968环氧增厚涂料、903聚合物水泥砂浆防水胶和HK—GFJ钢纤维硅粉混凝土对渡槽进行了全面的防渗补强处理,取得了良好的效果。 相似文献
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水泥基渗透结晶型防水材料是一种新型的防水材料,其属典型的涂布型躯体防水材料,依靠材料中特有的活性化学成分,通过和水的作用向混凝土内部渗透并形成不溶于水的结晶体,填塞混凝土毛细孔道,从而使混凝土致密、防水,增加混凝土的各项性能指标,抑制和修复混凝土由于应力和温度产生的裂缝,提高了整个混凝土坝的防渗效果。 相似文献
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●段家峡二级水电站厂房基础建于砂卵石层上,施工难度大,造成数处渗水、漏水,具有典型性。 ●聚氨酯防水材料TP—YT—928及TT—YT—928为缺少羟基的聚氨酯预聚体,其工作原理为灌入缝隙后,与水化合生成氨基化合物,体积并随之膨胀,达到防渗堵漏的目的。 ●实践证明,采用聚氨酯防水材料防渗堵漏效果甚佳,堵漏彻底可靠。 相似文献
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本文简要介绍了由中国水利水电科学研究院结构材料研究所,最新研制的一种新型防水材料。该系列材料具有高效防潮、抗渗性能好,可在大量涌水情况下实现快速封堵,能与多种材质结为一体,其粘结强度、耐腐蚀性、抗裂性及抗老化等各种性能均十分优异,是一种较为理想的刚韧性防水材料。 相似文献
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水泥基渗透结晶型防水材料相对传统的防水材料,解决了传统材料难以解决的施工工艺问题,提高了防水工程的工作效率,降低了防水工程的综合成本,满足了水工建筑物对耐久性的要求。本文介绍水泥基渗透结晶型防水材料的性能特点、与传统防水材料的性能比较、施工工艺及应用效果分析。 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