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用混凝土衬砌U形槽渠道的设计与施工 总被引:1,自引:0,他引:1
为了减少渠道的渗漏量,提高水的利用系数,辽宁省兴城市修建了一条16.6km的混凝土衬砌U形槽渠道。本文详谈了混凝土衬砌U形渠道的断面设计与施工,施工中应用了U-160型渠疲乏衬砌机。U型混凝土渠道为薄壳反拱结构,防渗效果好,输水能力强,占地面积比梯形渠道省1/3,且抗冻胀性能好。用混凝土衬砌的U形槽渠道减少了渠道渗漏,是一项重要的节水措施,应用衬机进行渠道施工,不令施工简单效率高,而且渠道断面尺寸 相似文献
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在山区半山区农田灌溉中,引小河流自流灌溉的较多,笔者在1994年设计了黑龙江省宁安市镜泊乡夹吉河灌区,该灌区耕地多集中在夹吉河两侧,宽度在0.5~2公里之间,设计灌溉面积 5 000亩,最大引水流量 0.6 m3/s,河流比降在 1/50~1/250,耕地坡度也多在此变化。渠道选线因受山坡、地形、公路及下级渠道的限制,沿公路布置,渠道比降较大,平均在1/50左右,如按渠道比降在(1/10~1/3)建陡坡,大于1/3建跌水的设计原则,消能建筑物数量相当多,且该灌区消能建筑物一般需考虑冻害因素,基础较深,所以工程造价高,如要跌水、陡坡等消能建筑物全部配套,引水灌溉得不偿失,将失去旱改水的机会,1989年乡政府曾动员村民建坝开渠改了 1000亩左右水田:因渠系建筑不配套,加之坡水入渠,渠道被冲的乱七八遭,维修费用逐年增加,水田面积越来越少,笔者在设计该灌区时采取防渗衬砌同消能相结合的办法,即利用硷允许抗冲流速比土渠抗冲流速大,糙率比土渠的糙率小的特点,在渠道比降大于 1/50的渠段直接用硷板衬砌,衬砌段尾部多与倒吸虹或渡槽连接(比降大段底处多是坡水沟)尾部不设消力池利用倒吸虹进出口做竖井消能或渡槽出口连接段做消能段... 相似文献
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重点论述了渠道混凝土机械化衬砌的特点及容易产生的质量问题,根据南水北调中线京石段应急供水工程和安阳段渠道工程混凝土机械化衬砌的施工实践经验,总结出了关于渠道混凝土机械化衬砌的操作流程和质量控制方法,对以后类似渠道混凝土衬砌工程具有一定的参考价值。 相似文献
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忻州地区,灌溉用水占到农业用水的90%以上,修成固定渠道1.3335km,累计防渗渠道4139km防渗长度占31%,全区渠道的渠系利用系数不达0.45、60%以上的损失在沿途渠系上,因此,搞好渠道防渗节约灌溉用水是缓解当前资金投入紧缺、水资源不足的有效途径之一。在渠道防渗措施中主要采用五种防渗型式:(1)浆砌石;(2)混凝土预制板;(3)现浇混凝土;(4)塑料薄膜;(5)混合型(浆砌石衬砌与混凝土抹面、渠底混凝土与浆砌石侧墙衬砌勾缝、塑膜铺渠底与混凝土预制板护坡)。通过对渠道防渗破坏原因分析后提出在渠道防渗措施中应改进的几点意见。 相似文献
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油故渠位于引黄入冀衡水湖输水干渠首段,是引黄入冀衡水湖配套工程项目之一。油故渠衬砌工程全长4.5km,衬砌高度4.0m,渠道采用现浇混凝土平板结构。该工程建设规模为中型,设计混凝土等级为C20,抗渗标号为S4,抗冻标号为F100,分2个标段施工,第一标段长2500m,第二标段长2000m。枣强县水利建筑工程队承担第一标段的施工任务,工程量为土方开挖64369.4m3,土方回填19915m3,砂垫层3458.3m3,混凝土11608.3m3。1土方工程11土方开挖土方开挖采用人、机结合的方法。首… 相似文献
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在引大入秦东二干渠秦王川明渠进行了300m(岩石基础)喷混凝土衬砌渠道试验,试验段长2.5m、5m和10m,有钢筋混凝土和混凝土几个层次,施工速度明显快于现浇混凝土衬砌,且经济效果良好,除10m段分缝过长不宜采用外,其它试验段质量良好,是值得推广运用的一种渠道衬砌方式。 相似文献
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土渠输水,由于渗漏,渠系水利用系数只有0.5左右。人们采用混凝土衬砌渠道内被,渠系水利用采数可提高到0.8~0.92。但由于温差作用,会导致衬砌渠道破裂,渠系水利用系数就明显的有所下降。河南省南阳市鸭河水库建区采取堤旁栽柳,成功地解决了这一难题。现简介如下:一、 相似文献
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文中采用正向递推水量平衡法对重点灌区渠道水利用系数进行了计算,并在运用实测结果和计算结果相结合对各种影响因素进行综合分析的基础上,建立了渠道防渗长度比和渠系水利用系数之间的关系,由此推出全省不同地区、各类灌区及全省的渠系水利用系数,为解决全省灌区渠系渗漏损失的估算提供了新的技术路线。 相似文献
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泾惠渠灌区是陕西省主要产粮区之一,灌区降水径流等水资源对于灌区的农业生产关系重大,分析灌区降水径流特性,明确灌区降水径流的主要影响因素,是灌区合理规划利用各种水资源的基础。降水径流等水文要素成因复杂,受气候因素影响具有周期性震荡特性,采用能够降噪和降维的奇异谱分析(SSA)方法对泾惠渠灌区降水径流时间序列震荡特征进行分析。分析显示,灌区降水径流时间序列均具有准3~4 a,9~12 a,18~22 a的周期性,与东部季风、太阳黑子等现象的周期性活动关系密切。由此表明,泾惠渠降水径流主要受东部季风的影响,且受太阳黑子等大尺度周期性因素的综合影响。 相似文献
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南水北调东线工程大多是利用现有的湖泊和河道进行凋蓄和输水,目前这些湖泊和河道的水污染问题突出,社会各界对南水北调东线一期丁程的治污及其未来效果极为关注。将2002—2003年东线工程输水干线水量、水质资料与东线治污规划成果相结合,比较分析东线工程沿线特别是南四湖地区的治污前景,在切实保证东线治污规划有效发挥作用的前提下,东线工程的北调水质有望实现全线Ⅲ类水质目标。 相似文献
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Water Productivity in a Rigid Irrigation Delivery System 总被引:4,自引:2,他引:2
The rotational irrigation water delivery (warabandi) system practiced in the Indus river basin of Pakistan has continued for 100 years. Irrigation water allocated to the farmers
under the warabandi system is proportional to farm size and is fixed. This rigid allocation system has been partly justified by its contribution
to social equity though this may have been at the cost of economic gains. In order to assess the operation of warabandi’s basic rules, a farmers’ survey was completed from 124 farmers located on five watercourses. A questionnaire was administered
to each farmer and farm management data were gathered. As fresh water resources are under stress and becoming scarce their
efficient use in all applications should be assured in water allocations. It is shown from the survey results that water allocation
based on very limited criteria does not maximize the socio-economic benefits gained from the use of scarce water. Thus, it
is suggested that the existence or non-existence of fresh groundwater resources along with other critical variables should
be taken into consideration when making canal water allocation decisions. Missed water deliveries due to failure of the canal
system appear to be the largest cause of losses. Water charges need to be increased to fund large improvements in canal maintenance
programs. It is pointed out that a framework should be developed as a tool to improve water productivity for Pakistan. This
should include: consideration of the gross area of a tertiary canal, sensitivity of crop growth stage to water shortage, crop
value, bias of allocation towards most water use efficient areas and water use efficient crops, the potential losses from
water deficiency. 相似文献
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In order to determine water losses in irrigation canals, a systematic approach was developed, consisting of two main components: a seepage simulation model and a hydraulic simulation model. The SEEP/W module of the Geo-Studio software was used to simulate the seepage rate, and the Hydrologic Engineering Center-River Analysis System (HEC-RAS) hydrodynamic model was used for hydraulic simulation. Different operation scenarios were designed to investigate all possible situations in daily operation of water distribution and delivery systems. The seepage simulation results show that the seepage losses were higher at the bottom and corners of the canal, because the hydraulic gradient was affected by the hydraulic load. The hydraulic simulation results show that due to physical and management infrastructure (using non-automated and operator-based regulation structures), operational losses accounted for a significant volume of losses compared to seepage losses. In most operation scenarios, the maximum seepage loss was 10%, and the remaining 90% was related to operational losses. It is concluded that any factor (decrease or increase of inflow to the canal) that causes an increase or decrease of operational losses is ultimately a determining factor in reducing or increasing total losses. Therefore, management approaches should be adopted to improve performance of the system and reduce losses, especially operational losses, by improving the operation methods of water level regulation and off-take structures. 相似文献
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加快小湾水电站的开发 促进东西部地区资源的优化配置 总被引:1,自引:0,他引:1
小湾水电站规模巨大,又具有良好的调节性能,可对下游各电站乃至云南系统内的水电站群发挥巨大的补偿效益,是澜沧江中下游水电基地的关键工程,也是理顺云南电力系统电源结构不合理状况和满足云南国民经济发展电力要求不可替代的工程,还是国家西电东送的战略工程。 相似文献