本文選題：復合襯砌 + 凍脹破壞��； 參考：《石河子大學》2014年碩士論文

【摘要】：水資源短缺是一個全球性問題，我國是一個水資源嚴重緊缺的國家。我國人均水量遠低于世界平均水平，僅為全球人均水量的四分之一，排在世界第110位。而我國是農(nóng)業(yè)大國，水資源短缺和水資源不合理地開發(fā)利用造成的浪費現(xiàn)象制約著我國農(nóng)業(yè)的發(fā)展。農(nóng)業(yè)水資源浪費主要體現(xiàn)在灌溉方面，我國農(nóng)業(yè)灌溉用水達到了農(nóng)業(yè)用水量的九成以上，而渠道輸水過程中因滲漏造成的損失占農(nóng)業(yè)用水量的近一半，達到我國總用水量的三分之一。為有效減少渠道輸水損失，發(fā)展節(jié)水農(nóng)業(yè)，渠道襯砌防滲工程被廣泛使用。但在我國北方寒冷凍土區(qū)，普遍存在渠道凍脹破壞現(xiàn)象，近年來膜料和混凝土剛柔結合的復合襯砌形式具有適應變形，防滲抗凍等特點，被廣泛采用，，但對復合襯砌形式防凍害缺乏具體的數(shù)學計算。本文在分析總結大量文獻基礎上，做了以下工作： （1）討論了渠基土壤產(chǎn)生凍脹的機理及影響因素，分析了各種形式渠道的破壞特征，總結了渠道防滲抗凍脹的基本措施。 （2）針對梯形、弧底梯形和U形三種斷面的膜與混凝土結合的復合襯砌渠道，從實際工程出發(fā)，根據(jù)渠道凍脹的基本規(guī)律，通過假設建立了復合防滲襯砌渠道凍脹破壞的力學模型，給出了內力計算公式、抗裂驗算公式并進行了厚度驗算。通過計算表明，采用土工膜與混凝土結合的復合襯砌形式與素混凝土襯砌形式相比，三種斷面渠道的有效凍脹力分別減小4.9%、2.6%、7.7%；有效切向約束力分別減小11.3%、7%、19.2%；渠道坡板拉應力分別減小16.7%、3.9%、8%；渠道底板拉應力分別減小6.1%、4%、7.5%，從力學角度證明了復合襯砌形式有利于渠道的防滲抗凍脹。 （3）利用ANSYS有限元分析軟件對梯形、弧底梯形和U形三種斷面的復合襯砌渠道的凍脹進行了數(shù)值模擬，得到了其溫度場、應力變形場，并進行了分析。溫度場等值線與襯砌板面平行分布，在坡板頂部位移值最大；梯形渠道在坡板與底板交界處應力值較大，弧底梯形渠道弧形底部應力值較大，U形渠道弧底應力值較大；陰坡應力值、變形值均大于陽坡。模擬結果與實際凍脹情況相符合，與力學分析相互印證，揭示了渠道凍脹破壞的機理。 通過軟件模擬結果和力學模型計算結果對比分析，復合襯砌渠道凍脹力的分布和凍脹變形的規(guī)律基本一致，渠道的凍脹破壞是在水分、溫度、土質等因素共同作用下發(fā)生的，說明了本文提出的簡化力學模型和有限元模擬方法是可行的，對復合襯砌渠道的進一步應用具有現(xiàn)實意義。
[Abstract]:Water shortage is a global problem, China is a serious shortage of water resources. China's per capita water is far below the world average, only 1/4 of the world's per capita water, ranking 110th in the world. However, China is a big agricultural country. The shortage of water resources and the waste caused by unreasonable exploitation and utilization of water resources restrict the development of agriculture in China. The waste of agricultural water resources is mainly reflected in irrigation. The agricultural irrigation water consumption in our country has reached more than 90% of the agricultural water consumption, and the loss caused by leakage in the course of canal water conveyance accounts for nearly half of the agricultural water consumption. It reaches 1/3 of the total water consumption in China. In order to effectively reduce channel water loss and develop water-saving agriculture, canal lining anti-seepage engineering is widely used. However, in the cold and frozen soil regions of northern China, the frost heaving failure of the canal is common. In recent years, the composite lining with the combination of membrane material and concrete rigid and flexible has been widely used because of its characteristics such as adaptability to deformation, anti-seepage and anti-freezing, etc. However, the concrete mathematical calculation for the frost damage of composite lining form is lacking. Based on the analysis and summary of a large number of literatures, the following works have been done in this paper: (1) the mechanism of frost heaving in canal soil and its influencing factors are discussed, and the damage characteristics of various forms of canal are analyzed. The basic measures to prevent seepage and frost heaving of canal are summarized. (2) aiming at the composite lining channel of trapezoid, arc bottom trapezoid and U-shaped section, according to the basic law of channel frost heaving, The mechanical model of frost heaving failure of composite impervious lining canal is established by assuming that the internal force calculation formula and crack resistance checking formula are given and the thickness check calculation is carried out. The calculation results show that the effective frost heaving force of the three cross-section canals is decreased by 4.92.6and 7.7in the composite lining with geomembrane and concrete, and the effective tangential binding force decreases by 11.37.2and 19.2respectively. The tensile stress of channel slope is reduced by 16.7and 3.9. the tensile stress of channel bottom is decreased by 6.1and 7.5. from the angle of mechanics, it is proved that the composite lining is beneficial to the anti-seepage, anti-frost and anti-heaving of the canal. (3) the trapezoid is analyzed by ANSYS finite element analysis software. The frost heaving of the composite lining channel with three types of arc bottom trapezoid and U-shaped section is simulated numerically. The temperature field, stress and deformation field are obtained and analyzed. The temperature field isoline distributes parallel with the lining slab surface, the displacement value at the top of the slope plate is the largest, the stress value of trapezoidal channel is larger at the junction of slope slab and bottom slab, and the stress value of arc bottom is larger than that of U-shaped channel. The stress and deformation of shady slope are higher than that of sunny slope. The simulation results are in agreement with the actual frost heaving, and the mechanism of channel frost heave failure is revealed. By comparing and analyzing the results of software simulation and mechanical model calculation, it is found that the distribution of frost heave force and the law of frost heave deformation are basically the same, and the frost heave failure of the canal occurs under the joint action of water, temperature, soil quality and so on. The simplified mechanical model and finite element simulation method proposed in this paper are feasible and have practical significance for the further application of composite lining channel.
【學位授予單位】：石河子大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TV672;TV698.26

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