| In the agricultural water conservancy project,channels are the major buildings of water transmission and distribution.However,the irrigation channel project has a lot of problems,including low design standard and water resources use efficiency and poor construction quality,therefore it plays a significant role to constrcut safe and reliable water transmission and distribution channels and design optimal canal systems in improving the irrigation water use efficiency and the development of China’s water-saving agriculture.At present,the channel sections with rectangle,trapezoid,U-shape and trapezoid with curved slope toe and arc bottom are widely used in most parts of China.In recent years,parabolic channels have been applied and promoted in the lining and anti-seepage project construction because of its advantages of continuous section and great hydraulic performance.Based on the previous research results and application of the methods of channel optimization and structural analysis,the fabricated parabolic concrete channels was put forward from the level of productization and standardization,meanwhile its optimal structural analysis was also proposed in this paper,so as to provide technical support for the further popularization and promotion of the parabolic concrete channels.The main achievements are as follows:(1)This paper expounds the significance of determining the structure of the optimal concrete channel by looking at a large number of relevant literature at home and abroad,analyzing the development status of the domestic and foreign lining channel and anti-seepage technology at home and abroad and the research and application of the fabricated concrete channels,and summarizing the method of channel section optimization and structural analysis.(2)A mathematical model of parabolic channel section optimization with the difference between calculated flow rate and design flow was established.Particle swarm algorithm was introduced into the parabolic channel section optimization calculation and global search was carried out with the constraints of the noneroding velocity,the non-silting velocity and width-depth ratio of channel.The shape parameter a and the design depth h of the optimal design of the parabolic channel section were determined.(3)Taking the parabolic concrete channel of Wuhangyuan branch in Shitouhe irrigation area of Shaanxi province as an example,the second parabolic channel section is optimized.The results show that the optimal shape parameter a is 5.06 and the optimal design depth h is 0.3982 m.Compared with the original design,the calculated area,earthwork and amount of lining concrete of the channel respectively decreased by 0.1021%,0.5683% and 1.8309%,and the area of the project also reduced with it.(4)The fabricated parabolic concrete channel was proposed,and the structural type of the fabricated parabolic concrete channel was constructed according to the optimal section of the parabolic channel.On the basis of ABAQUS-6.14 finite element analysis software,this paper analyzed the stress and displacement field of the fabricated parabolic concrete channel and obtained its distribution law,guiding the design of the fabricated parabolic and lining concrete channels. |
