【作者】 陈涛；

【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， 2004， 硕士

【摘要】 我国幅员辽阔，但水资源缺乏。因此，节约用水，走可持续化的发展道路是我国农业的发展方向，做好渠道防渗工程是实现节水型农业的基本措施。在我国，冻土地区和季节性冻土地区占国土面积的 3/5，渠道破坏主要表现为衬砌体的冻胀破坏，本文在阅读和分析大量文献资料的基础上，论述了我国渠道防渗事业的发展历史和现状；从衬砌的断面形式和结构形式等方面介绍了目前渠道防渗工程的几种主要衬砌形式的各自特点，分析了曲线形渠道衬砌形式如 U 形渠道、弧底梯形渠道、弧脚梯形渠道较目前常见的梯形渠道的优越性，并提出一种新型的断面形式——准梯形断面形式供大家探讨；分析了复合衬砌形式较单一衬砌形式的优越性；分析了各种形式衬砌的冻胀机理和破坏形式，总结了防治渠道冻胀破坏的基本措施，并对以前涉及很少的衬砌结构的内力计算问题进行了初步探讨，以期建立具有实用价值的力学模型，服务于生产和科研。寒冷地区渠道衬砌冻胀破坏非常普遍，研究简单准确便于工程设计的力学模型极为必要，为此通过对梯形渠道砼衬砌冻胀破坏机理的分析，通过恰当的基本假设：①指出了梯形砼衬砌渠道的整体结构为在法向冻结力、切向冻结力、法向冻胀力共同作用下的薄壳拱形结构，整体结构属压弯组合变形。②提出了梯形砼衬砌渠道整体结构冻胀破坏的力学模型，通过对模型的求解给出了该薄壳拱形结构控制内力计算及最大剪应力计算公式，并结合砼板抗裂条件给出了冻胀力、胀裂部位、冻胀抗裂衬砌板厚度及抗冻破坏验算的一系列计算方法。③指出了衬砌板上各种冻结力、冻胀力的大小及方向是相互依存直接相关的，最大冻结力是土质、负温及水份状况的综合指标，只要根据经验或实验确定了最大冻结力、力学模型就可求解。工程实例计算表明本模型是安全合理、简单实用的。更多还原

【Abstract】 Our country has a vast territory, but lack water resources. While, saving water resourcesand sustainable development will be the only direction of our agriculture. Building channelseepage controlling engineering is one of the basic methods to realize the aim. There are more than 3/5 of our territories are belong to forest area, frost heaving damageis the main destroying forms of the channel in the region. Based on the observation andanalysis of large number of literature references, the history and the development of channelseepage controlling techniques are discussed in the paper. Give a presentation of theproperties of channel lining from the cross section and the structure of the channel; analyzedthe advantage of the curve type channel (such as U type section, trapezoid section with arcbottom and trapezoid section with arc foot) than trapezoid section channel by diagram anddata, put forward a new type section channel, para-trapezoid section; analyzed the damagemechanism and forms of different lining form, summarized the basic methods of controllingfrost heaving damaged, probed into the internal force calculation problem of lining structurethat discussed merely at before, expect to build a sort of mechanics model to serve theengineering. By thorough analysis of the damage mechanism of frost heaving on the concrete lining ofthe channel with trapezoidal cross section, this article presents the following conclusions:First, it points out that the calculating diagram of the lining plates of canal bottom and slopesare two–ends-simply-supported beam. Both of them are combined deformation membersunder the loads of bending and compressing. Second, it gives the mechanics models of frostheaving damage of the concrete lining plates of the canal with trapezoidal cross section. Andpresents the calculating formula of the control internal forces and maximal tensile stresses ofthe canal slope lining plates and the canal bottom lining plates. Furthermore, by considering<WP=7>the conditions of crack resistance of the concrete plates, it presents a series of calculatingmethods of frost heaving forces，position of expansion cracks，proper depth of the liningplates to prevent frost heaving and cracks occurrence , and checking calculation forprevention of frost heaving. Finally, it also elucidates that the intensity and direction of thefrost heaving forces，adfreezing forces and interactionally restricting forces, except for thegravity, are all interdependent , and they all can be expressed as the function of the adfreezingforces. Moreover the adfreezing forces is a comprehensive reflection of soil quality, negativetemperature and the status of moisture, thereby the mechanics models can be solved providedthat adfreezing forces is determined according to the practical experience or experiment.Subjecting the models to the field engineering calculating test shows its safety, rationality,simpleness and practicability.更多还原