| Our country is a shortage of water resources, the development of water-saving agriculture is an effective way to ease the contradiction between supply and demand of water resources. However, a serious loss of irrigation water seepage during transport, leading to low utilization coefficient of irrigation water. Canal anti-seepage with Concrete Lining is currently the most widely used measure of water-saving engineering technology, because it can effectively reduce seepage losses for agricultural irrigation. In recent years,large amount of canals with lining have been built. Parabola-shape canal with concrete lining is gradually popularized because it has the advantages of good hydraulic condition, small occupation area and good performance of anti-frost property. However, concrete lining canals often suffer from serious frost damage in due to the negative temperature in the area of seasonal frozen region, which directly affects the normal operation of the project and effect of seepage, which seriously restricted the popularization of impervious engineering technology.Based on previous studies, through the reference and analysis of various literatures, this paper expounded the significance of impervious, discussed the development status of anti-seepage and anti-frost, summarized the frost heave mechanism and characteristics of different sections of canal. By analyzing the frost heaving damage characteristics and reasons of parabolic-shape canal with concrete lining, this paper established the mechanics models of frost heave damage and used the ANSYS to simulate the frost heave. The main research and results are in the following several aspects:(1) This paper analyzed the main factors influencing the frost heave of canal, summarized the frost heaving damage mechanism and characteristics of different sections of canal and discussed the characteristics of frost heaving damage of parabolic-shape canal with concrete lining.(2) Calculating the optimal hydraulic section of quadratic parabola-shape canal and cubic parabola-shape canal, determining the Section form of concrete lining canal is quadratic parabola-shape by comparing, and deducing the calculation formula of hydraulic parameters for economic practical section of quadratic parabola-shape canal.(3) According to the characteristics and reasons of frost heaving damage of parabolic-shape canal with concrete lining, calculating diagram of the parabolic-shape structure was established by determining the distribution of normal frost heaving force, tangential freezing force and gravity with the proper hypothesis. Then the mechanic model of parabolic-shape canal was established and a series of calculation formula was worked out, including calculation formula of internal force and moment, the destruction checking of frost heaving damage.(4) Regarding the frozen soil as isotropic elastic material and taking the frozen soil the canal lining as an integrality, the numerical simulation of frost heave was carried on with the software ANSYS, and obtained the distribution about temperature field, the stress and the deformation field. This shows that the mechanics model and numerical simulation have a great significance on the engineering design of similar canal. |
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