【作者】 辛英华；

【导师】 王正中；

【作者基本信息】 西北农林科技大学 ， 水利水电工程， 2008， 硕士

【摘要】 我国是一个水资源严重短缺的国家,人均水资源占有量排在世界第109位,仅为世界平均水平的1/4。渠道防渗是我国目前使用最广泛的节水工程措施,它可以极大地减少农业灌溉用水的浪费,节水潜力巨大。但是,在我国,冻土地区和季节性冻土地区占国土面积的3/5,渠道防渗工程普遍存在着严重的冻害问题。高地下水位区灌排渠道因其特殊的水文地质条件造成对其认识不足。长期以来,工程实践中对高地下水位区灌溉渠道的衬护,缺乏简捷有效且经济适用的方法,许多工程仍采用传统的渠道防渗衬砌,致使大量已建渠道经过短期使用后,渠道边坡失稳,滑塌破坏严重,严重制约了工程效益的发挥。所以,如何防治高地下水位区混凝土衬砌渠道的冻胀破坏已成为一个非常现实的困绕灌区健康发展的问题。(1)在阅读和分析大量文献资料的基础上,从衬砌的断面形式和结构形式等方面分析了目前渠道防渗工程的几种主要衬砌形式的各自特点;总结了防治渠道冻胀破坏的基本措施,各种形式混凝土衬砌渠道冻胀机理及破坏特征等;(2)针对U形断面渠道的衬砌冻胀破坏特征、机理的分析,指出最优U形断面应是从结构和水力两方面考虑的,通过合理的假设,建立简单合理的力学模型,以衬砌体结构抗冻胀性能最优及水力最佳为原则,最终推出最优的U形渠道断面参数弧底圆心角和圆弧上部直线段的相对长度;(3)在分析高地下水位区灌排渠道滑塌、冻胀破坏特征及原因的基础上,针对性的采用滤透式衬护结构,通过结构措施从根本上解决了高地下水位条件下灌溉渠道滑塌和冻胀破坏等诸多工程难题,确保了灌排渠道的断面稳定和正常运用;并对以前涉及很少的高地下水位灌排渠道冻胀破坏机理及力学模型进行了初步探讨,将单位长度的空心框架衬护渠道按衬护面积折算,按全面衬砌渠道建立简单的对称力学模型,只需选取最大冻结力一个参变量,即可求解渠道衬砌板上的冻胀力;(4)用大型有限元软件adina对弧底梯形框架衬砌渠道和整体衬砌渠道冻胀进行数值模拟分析,获得其温度场、变形场和应力场,得到高水位区弧底梯形衬砌渠道冻胀受力及变形的基本规律,并通过对二者比较分析,得出混凝土框架衬砌渠道可以有效降低地下水位,增强衬护效果,控制渠道冻胀破坏,是解决高地下水位灌排渠道滑塌及冻胀破坏的有效措施。更多还原

【Abstract】 China is a serious shortage of water resources, water resources per capita amount ranked No. 109 in the world,it is only the world average level 1/4. The channel anti-seepage is our country uses the most widespread saving water mechanical control measure at present, it may reduce the agriculture irrigation water enormously the waste, the saving water potential is huge.But there are more than 3/5 of our territories are belong to forest area, frost heaving damage is the main destroying forms of the channel in the region. Because the high subsoil water level area fills a row of channel its special hydrogeological conditions to create to its understanding insufficiency. Since long, the project practice protects to the high subsoil water level area irrigation canal’s lining lacks simple and direct effective, and the economical suitable method, many projects still used traditional the channel anti-seepage lining work, the massive has constructed after the short-term use, the channel side slope jitter, collapses the destruction to be serious slippery, so,they have restricted the project benefit display seriously. Therefore, how to prevent and control the high subsoil water level area concrete lining channel’s heave to destroy has become one very realistically question to the irrigation area healthy development.(1)Based on the observation an analysis of large number of literature references, analysis of the current channel anti-seepage project of several major forms of lining their own characteristics from the lining of the cross-section of the form and structure of the areas ; Summed up the basic measures to prevent frost heaving channels destruction, and destruction of frost heave characteristics of various forms of concrete lining channels ;(2)Through analysising U-shaped cross-section of the channel lining frost heave damage features, the mechanism that should be the optimal U-shaped cross section from the structure and hydraulic two considerations, through reasonable assumptions, a simple mechanical model reasonable to lining of Optimal performance of anti-freezing water and the principle of the best, the ultimate optimal launch cross-section of the U-shaped channel parameters arc at the end of central angle and the upper arc of the relative length of a straight line; (3)Analysis the reason of high groundwater irrigation and drainage channels slump, the characteristics and causes of damage frost heave, through structural measures to fundamentally solve the high level of groundwater irrigation channels under the conditions of slump and freezing damage, and many other engineering problems, ensure the irrigation and drainage channels to ensure the stability and the normal application of section; Preliminary study on the past few involved in the high level of groundwater irrigation and drainage channels frost heave damage mechanism and mechanical model, Unit will be the length of the hollow framework for lining channels for conversion by lining area, according to a comprehensive channel lining to establish a simple symmetrical mechanical model, only need select a biggest adfreezing force parameter, then solves on the channel liner plate’s frost heaving pressure;(4)With the application of FEM software ADINA ,the paper simulates the frost heaving process of lining framework and the overall framework of lining Arc bottom trapezoidal channel, and has a deeply study on its temperature field, the stress and the deformation field, obtains the high water mark area arc bottom trapezoidal lining work channel heave stress and the distortion basic rule. Through the two comparative analysis, Concrete channels lining the framework that can effectively reduce the water table, enhance the contrast for effect, frost heave damage control channels, is solving the high level of groundwater irrigation and drainage channels slump and the destruction of effective measures to frost heave.更多还原