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鲁地拉围堰覆盖层深厚,透水性强,基础防渗采用混凝土防渗墙。防渗墙施工采用泥浆护壁、"钻劈法"成槽,深入基岩0.5m,采用泥浆下直升导管法浇筑混凝土,I、II期槽段采用接头管法连接;从围堰实际运行效果看,防渗效果良好。 相似文献
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薄混凝土防渗墙技术已广泛用于病险水库土石坝的防渗加固,本文通过一种新的施工方法--锯槽法在南阳市水库除险加固工程中的应用,对"锯槽法"建造薄混凝土防渗墙的施工工艺及技术要点进行了探讨,为中小水库建设提供参考. 相似文献
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尖山水库塑性混凝土防渗墙采用"钻抓法"成槽,泥浆护壁,"接头管法"连接,"泥浆下直升导管法"浇筑混凝土,从施工后的蓄水情况来看,坝体已无渗漏现象,防渗指标满足设计要求,对增加稳定、减少水资源流失起到重要的作用,为尖山水库更好地发挥作用提供了可靠的保证。尖山水库塑性混凝土防渗墙施工采用"钻抓法"成槽,泥浆护壁,"接头管法"连接,"泥浆下直升导管法"的成墙施工,作为尖山水库大坝渗漏除险加固的施工方案,并取得预期效果。 相似文献
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信房水库除险加固工程混凝土防渗墙施工技术 总被引:1,自引:0,他引:1
信房水库大坝建成已有40多年的历史,土坝坝体沉陷渗漏、老化及变形严重。混凝土防渗墙原设计施工方法为"两钻一抓"法,鉴于在土坝上使用重量大的抓斗给施工过程中带来的安全及质量隐患,经过设计方案的优化,采用"钻劈法"成槽,优质高效地完成了信房水库混凝土防渗墙的施工,各项指标满足要求。 相似文献
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库坝混凝土防渗墙冲击钻劈法施工中常见作业事故与防治措施 总被引:2,自引:0,他引:2
采用冲击钻劈法成槽的混凝土防渗墙施工在广西已成功建成 6座槽板式库坝 (堰坎 )混凝土防渗墙 ,结合实例介绍了在冲击钻劈法造孔和直升导管泥浆下浇筑混凝土两道主要施工工序中常见作业事故及防治措施 相似文献
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在调查浙江省近年来建设的山区水利枢纽工程的建设及运行情况的基础上,分析消能防冲结构存在的问题,研究相应的保护或加固技术,介绍消能防冲结构中纤维混凝土、石笼网、抛石混凝土等新材料、新技术的应用情况和适用条件。调查结果表明,闸底板及消力池底板表面采用纤维混凝土后,施工期温度裂缝明显减少,耐磨损性能有所提高,石笼网和抛石混凝土技术可以有效地提高抛石防冲槽等结构薄弱部位的抗冲能力。 相似文献
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介绍在苏丹上阿特巴拉水利枢纽项目塑性混凝土防渗墙施工中,采用液压抓斗、液压双轮铣槽机两种设备的联合施工技术,充分发挥各自的优势,保证整个防渗墙工程顺利完成。 相似文献
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万安水电站厂房混凝土温控设计和裂缝情况 总被引:1,自引:0,他引:1
万安水利枢纽主要建筑的混凝土工程量为153立方米,其中电站厂房44.43万立方米。万安枢纽的河床式厂房尺寸大,结构复杂。但厂房混凝土的裂缝却很少,其主要原因是针对厂房结构的特殊性采用了以下一系列温控防裂措施:(1)在尾水管大型钢筋混凝土框架结构中设置封闭块,以减或消除施工期温度应力;(2)以错缝为主,辅以宽槽及灌浆缝;(3)厂房分块尺寸在15-17米左右;(4)混凝土薄层、短间歇上升;(5)风冷加 相似文献
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随着地下连续墙施工技术发展,“L”形地连墙作为一种常见的异形地连墙被广泛应用于封闭地下围护结构设计施工中。由于成槽过程中,槽段及周边土体的应力变化复杂,“L”形地连墙的稳定性低于常规矩形地连墙。基于上限分析法,对“L”形地连墙成槽施工过程中的稳定性进行研究,提出“L”形地连墙稳定三维机动场模型,计算得出槽壁安全系数,揭示了异形地连墙槽壁失稳机理,并通过参数计算分析地连墙几何形状以及土体性质对槽壁稳定性的影响。对某地连墙工程进行计算,计算结果与现场超声波检测相吻合。研究结果可为异形地连墙的设计施工提供参考和理论依据。 相似文献
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《水科学与水工程》2016,(2)
In coastal areas with complicated flow movement, deposition and scour readily occur in submarine excavation projects. In this study, a smallscale model, with a high resolution in the vertical direction, was used to simulate the tidal current around a submarine excavation project. The finite volume method was used to solve Navier-Stokes equations and the Reynolds stress transport equation, and the entire process of the tidal current was simulated with unstructured meshes, generated in the irregular shape area, and structured meshes, generated in other water areas.The meshes near the bottom and free surface were densified with a minimum layer thickness of 0.05 m. The volume of fluid method was used to track the free surface, the volume fraction of cells on the upstream boundary was obtained from the volume fraction of adjacent cells, and that on the downstream boundary was determined by the water level process. The numerical results agree with the observed data, and some conclusions can be drawn: after the foundation trench excavation, the flow velocity decreases quite a bit through the foundation trench, with reverse flow occurring on the lee slope in the foundation trench; the swirling flow impedes inflow, leading to the occurrence of dammed water above the foundation trench; the turbulent motion is stronger during ebbing than in other tidal stages, the range with the maximum value of turbulent viscosity, occurring on the south side of the foundation trench at maximum ebbing, is greater than those in other tidal stages in a tidal cycle, and the maximum value of Reynolds shear stress occurs on the south side of the foundation trench at maximum ebbing in a tidal cycle. The numerical calculation method shows a strong performance in simulation of the hydrodynamic characteristics of tidal currents in the foundation trench, providing a basis for submarine engineering construction in coastal areas. 相似文献
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Anna Petit-Boix David Sanjuan-Delmás Carles M. Gasol Gara Villalba María Eugenia Suárez-Ojeda Xavier Gabarrell Alejandro Josa Joan Rieradevall 《Water Resources Management》2014,28(4):979-997
In a world with an increasing urban population, analysing the construction impacts of sanitation infrastructures through Life Cycle Assessment (LCA) is necessary for defining the best environmental management strategies. In this study, the environmental impacts of one linear meter of sewer constructive solution were analysed for different pipe materials and diameters used in Southern Europe; a unit of different sewer appurtenances (pump, manhole and inspection chamber) was also considered. The impacts of the pipe materials were compared considering different lifespan periods and high-density polyethylene (HDPE) turned out to be the worst option, being polyvinyl chloride (PVC) and concrete the most favourable ones. Few data are available on the material and energy flows in the installation stage; therefore, a comparative analysis of trenches with sand and concrete bedding was conducted. The results show that the installation stage represents up to 80 % of the total life-cycle impact of the constructive solutions. Concrete pipes with half-concrete/half-sand bedding are the best option and produce 20–30 % of the impact of HDPE pipes with concrete bedding. Hence, designers should focus not only on the pipe but also on the trench model. A methodology was presented to enable the impact aggregation of the different sewer elements, and Betanzos (Spain) was selected to conduct a pilot study in small cities. In the future, studies will need to incorporate the use and maintenance stage, as it is not standard and varies according to the physical features of the cities. Finally, this study provides basic concepts for developing eco-efficiency indicators. 相似文献
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埋地钢管在设计时需考虑管周土体和沟槽对钢管的影响,但土体力学参数和沟槽形态参数对钢管结构的影响研究不够深入。通过引入正交试验法,以钢管最大竖向变形和钢管顶、腰、底处环向弯曲应力为试验指标,进行回填土变形模量E1、砂垫层变形模量E2、垫层包角θ、沟槽底部开挖宽度B和沟槽侧壁倾角α关于试验指标的敏感性分析。研究表明:对钢管变形和应力敏感性较高的因素有E1、E2、α;B的敏感性较低;θ的敏感性最低。埋地钢管的土体变形模量高、沟槽窄对钢管结构有利,沟槽侧壁倾角影响较为复杂,需结合具体工程进行分析。研究成果可为合理选取埋地钢管的结构设计参数,提供一定的参考依据,同时也为类似问题提供一种分析思路。 相似文献