共查询到19条相似文献，搜索用时 455 毫秒
1.
王振铎 《中国农村水利水电》2006,(3):86-88
通过复合土工膜、改进PP纤维、土工格室等土工合成材料的科学研究，提出了复合土工膜料+5CM厚土工格室（或PP纤维）混凝土板的成套渠道防渗抗冻技术，经济地解决了原15-20CM厚混凝土板都不宜抵抗住的冻害问题，使工程造价降低了30%以上。 相似文献
2.
土工合成材料在冻胀区渠道防渗中的应用研究 总被引：7，自引：2，他引：5
王振铎 《中国农村水利水电》2006,(3):86-88,91
通过复合土工膜、改性PP纤维、土工格室等土工合成材料的科学研究，提出了复合土工膜料＋5cm厚土工格室（或PP纤维）混凝土板的成套渠道防渗抗冻技术，经济地解决了原15-20cm厚混凝土板都不宜抵抗住的冻害问题，使工程造价降低了30％以上。 相似文献
3.
聚合物纤维混凝土在渠道防渗中的应用 总被引：3，自引：0，他引：3
在渠道混凝土防渗工程中，防止或减少混凝土裂缝，提高混凝土的变形能力一直是主要技术问题之一。本文结合开水库灌区渠道防渗工程特点，对聚合物纤维混凝土的拌和工艺和主要性能进行了研究，并将研究成果应用于该工程的填方渠道防渗衬砌中，在基本不增加工程投资的情况下，渠道防渗混凝土的抗裂能力和抗渗能力显著提高，经济效益显著。 相似文献
4.
永舒榆灌区原有的配套工程不完善,几乎没有防渗措施,田间节水工程滞后,水利用率低,影响灌区效益的发挥.详细介绍复合土工膜结合PP纤维混凝土防渗技术的原理及其在灌区节水灌溉续建工程中的施工工艺.实践证明,该技术具有良好的防渗效果. 相似文献
5.
浆砌石土工膜防渗技术在渠道防渗中的应用 总被引：1，自引：0，他引：1
水利工程建设中渠道防渗失修是普遍存在的问题,在滹沱河灌区大型重点续建配套与节水改造工程中,针对以往浆砌石护坡防渗和混凝土预制板防渗存在的问题,采用浆砌石土工膜防渗新形式,并在施工工艺上进行了改革,取得良好效果。 相似文献
6.
防渗渠道的年久失修是目前灌区普遍存在的问题，滹沱河灌区在１９９０～１９９１年的干渠防渗工程改造中，针对以往混凝土预制板防渗和浆砌石护坡防渗存在的问题，采用浆砌石──土工膜防渗新形式，并在施工的放线、砌筑、勾缝技术上进行改革，取得良好效果，工程效益显著。 相似文献
7.
防渗渠道的年久失修是目前灌区普遍存在的问题，滹沱河灌区在１９９０－１９９１年的干渠渗工程改造中，针对以往混凝土预制板防渗和浆砌石护坡防渗存在的问题，采用浆砌石－－土工膜防渗形式，并在施工的放线、砌筑、勾缝技术上进行改革，取得良好效果，工程效益显著。 相似文献
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9.
兴建于1993年的多伦县大河口水电站，为解决工程投资与效益矛盾及水库拦河坝施工不利因素，通过研究，解决了坝体应用土工膜垂直心墙防渗的一系列技术问题，在含砾量高于20%，最大坝高19.8m的砂砾土坝中，建筑土工膜防渗体垂直心墙替代传统的粘土防渗体，获得了良好的防渗效果和显著的经济效益. 相似文献
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11.
防渗渠道输水损失的估算 总被引：4，自引：0，他引：4
渠道防渗已成为我国大型灌区改造的主要手段 ,以提高水资源的利用率 ;如何估算防渗渠道的水量损失 ,已成为评价灌区改造的重要技术问题。在概括渠道输水损失的各种估算理论和方法的基础上 ,揭示了流量指数型估计式 σ=A/ Qm(% )对于防渗和非防渗渠道都具有广泛的适用性。并基于全国范围内的实测资料统计分析 ,对影响估计式参数的因素及规律性进行了深入分析 ,建议对防渗或非防渗渠道的渠道渗漏损失均采用该估计式 ,防渗渠道的参数可通过现场静水试验求得 ,或直接对透水性系数进行折减。 相似文献
12.
Seepage from earthen irrigation canals represents substantial water loss in irrigation districts. Historically, the determination of canal seepage was accomplished using the inflow-outflow method with propeller and electromagnetic type flow meters. This method was difficult, time consuming, and limited by measurement device accuracy. In recent years, advances in technology have lead to the widespread use of Acoustic Doppler Current Profilers (ADCP) for discharge measurements in streams and rivers. Even though ADCP use has become widespread for stream discharges, studies to determine canal seepage using this new technology are limited. Using an ADCP, extensive field measurements were conducted in the Middle Rio Grande Conservancy District. This paper describes the ADCP measurement protocol used to measure irrigation canal seepage and presents predictive equations for determining canal seepage based on flow rate and canal geometry. 相似文献
13.
有机硅掺入混凝土具有提高其抗压、防渗、抗冻、抗钢筋锈蚀、防龟裂和减水、缓凝、自养混凝土及降低混凝土碳化速度等性能；对木结构具有极强的防水、防潮、防火、防腐等作用。通过分析揭示了有机硅的特性和在水利工程中的实用意义，为渠道防渗提供了依据。 相似文献
14.
针对预制U型混凝土渠道高抗裂性和高抗渗性的要求,结合宾阳那洪水库灌区渠道防渗工程特点,通过双掺粉煤灰及聚丙烯纤维实现预制U型混凝土渠道高抗裂性和高抗渗性,研究结果表明：粉煤灰掺量为胶凝材料总量的20%,聚丙烯纤维掺量为0.9kg/m3时,预制U型混凝土渠道的抗裂性和抗渗性显著提高,经济效益显著。 相似文献
15.
Of the many types of canal linings in the world, concrete, compacted earth and buried plastic membrane linings are most commonly used. Another type of canal lining — plastic membrane-concrete thin slab lining — has been used in China since 1975. It has the advantages of both plastic and concrete linings, including good seepage control, smooth lining surface, steeper side slopes, effective film valve to eliminate external water pressure, reliability, durability, and lower construction cost. This type of canal lining is a viable alternative to other types of linings, especially in developing countries where the cost of labor is low or farmland is limited. 相似文献
16.
Modelling the effect of canal bed elevation on seepage and water table rise in a sand box filled with loamy soil 总被引：2，自引：0，他引：2
The HYDRUS 2D finite difference two-dimensional water balance model was experimentally tested for transient and steady state
seepage flux, mound height, and piezometric water level from soil surface as a function of time and horizontal distance from
the centre of the canal (half width = 45 cm) under different canal bed elevations (20, 0, −40, −80 and −120 cm denoted as
experiments D1, D2, D3, D4 and D5, respectively) and constant water head of 5 cm in a sand box (200 cm × 170 cm × 150 cm)
filled with Hisar loam soil. Differences of means between measured and predicted values of infiltration flux, seepage flux
and mound height as tested by paired t test were not found significant (P = 0.05). Seepage flux and mound height increased with increasing canal bed elevation. Phreatic level depths were everywhere
much shallower than the piezometric water level depths in experiments D1, D2 and D3. However, in experiments D4 and D5 both
phreatic and piezometric levels were at similar depths. The seepage parameters and mound height increased, and water table
depth decreased, linearly with increasing canal bed elevation. Lowering the canal bed to 120 cm below the soil surface reduced
the seepage rate to that of lined canals. The projections in a large flow domain also revealed that lowering the canal to
−2 and −4 m below soil surface stabilized the water table at 2.5 and 4.5 m below soil surface, respectively. The practical
implications are that open drains should be used for irrigation in areas underlain with a brackish groundwater aquifer and
gravity canals may be allowed only where groundwater aquifer is of good quality and sub-surface water withdrawal is practiced
for irrigation. 相似文献
17.
《Agricultural Water Management》2006,83(3):243-251
Irrigation schemes have contributed to the availability of water not only for agriculture but also for domestic use by rural households. In the Uda Walawe irrigation scheme in southern Sri Lanka, irrigation canals are being lined with concrete to save water, meant to enable extension of the irrigated area. The effects of lining on the availability of water for multiple uses were investigated by field measurements of water levels and by an inventory of the perceptions of changed water availability by the population through focus group discussions. From the measurements it was determined that canal seepage provides an important contribution to groundwater recharge. It was estimated that after concrete lining the annual groundwater recharge in the irrigated areas will be reduced by approximately 50%. This saves a substantial amount of water that can be used to extend the irrigation area so more people can benefit from the available irrigation water. However, in the currently irrigated areas lining will have negative impacts by lowering groundwater levels due to a reduction in seepage from canals. This seepage contributes to the recharge of shallow wells used by the population to obtain water for drinking and cooking. The perception of the population was that enough water remains for domestic use. Other changes, such as reduced yields from home gardens were considered to be more important. Despite these negative impacts the expected positive impacts in the extension area justify, from a social equity point of view, concrete lining as a measure to redistribute the available water over the Uda Walawe area. 相似文献
18.
为了对渠道防渗工程的方案进行优选,采用模拟退火粒子群优化投影寻踪方法对渠道防渗模式进行优化评价.优化粒子群算法,使其在退火过程中接受优解,且还以一定的概率接受差解.同时利用模拟退火粒子群算法在搜索过程中具有概率突跳的能力,有效地避免搜索过程陷入局部极小解,提高了算法的收敛速度和精度.将该模拟退火粒子群算法与投影寻踪结合,建立了模拟退火粒子群优化投影寻踪模型,将该模型应用到灌区渠道防渗模式优化评价中,选取10个指标作为评判因子,提出适合该地区的干渠渠道防渗工程优化模式,其优劣排序依次为方案Ⅳ、方案Ⅱ、方案Ⅲ、方案Ⅴ、方案Ⅰ.研究表明模拟退火粒子群优化投影寻踪的评价模型对灌区渠道防渗模式进行综合评价是切实可行的,模拟退火粒子群优化投影寻踪的评价方法在解决实际问题中展示了其优越性,并取得了良好的应用效果. 相似文献
19.
Laboratory flume test was conducted to investigate the effect of flowing water an soil-cement canal tiles. For this purpose, soil-cement tiles were constructed from different soils at various cement contents. A flume, 3 metre long and 100 mm wide, was lined with the tiles and the lined bed was subjected to flow velocities of around 2 m/s for a period of 7 days. The tiles made from coarse-textured soil (sandy loam and silt loam) aggregates of 5 mm and from fine textured soil (clay loam) aggregates of 2 mm size were found to be intact and smooth even when constructed at a cement contents lower than that needed to meet the durability requirements.Attempts were also made to measure seepage losses of soil-cement tile linings. A channel section of approximately 1 metre length with a side slope of 1:1 was constructed in the laboratory with the tiles and seepage losses measured by the ponding method were found to be in the range of 0.00123–0.00343 m3/m2/day.The results clearly suggest that soil-cement tiles (irrespective of type of soil) made with 2 mm or less size of soil aggregates are erosion resistant and due to very little or negligible rates of seepage losses, the soil-cement tile lining of irrigation canals is expected to be very promising especially in the areas where irrigation water is costly. 相似文献