On The Design Of Frost Heave Of Lining Canal In Liaoning Coastal Irrigation District

The relevant experimental data shows that the leakage loss of water can be reduced by 70%?90%by means of seepage prevention measures and the main method of canal seepage control in China is concrete canal seepage control.In the north due to reasons such as climate,there is a frost heaving damage phenomenon in concrete canal seepage control which is relatively serious.And the irrigation district of Liaoning Province is mostly in the coastal area,so studying the anti-frost damage of irrigation channel in coastal areas of Liaoning Province has great significance to improve the durability of engineering and the rice production in coastal areas of Liaoning Province,and curb the waste of irrigation water more effectively.Firstly,selecting the irrigation area within 100km of coastline in Liaoning province,three indexes of underground water level,distance from coastline and designing irrigation area were analyzed by fuzzy clustering method.The coastal irrigation area is irrigation area which is 60km away from the coastline and below 3m underwater water level.In order to study the frost heaving of lining canals in coastal irrigation area of Liaoning Province,the coastal irrigation area is divided into four areas according to the properties of soil,underground water level and temperature similarity,in which Huludao and Jinzhou are same areas,Dandong and Dalian are same areas,Yingkou and Panjin are same areas,and selecting Haibin irrigation area,Dawa irrigation area,Yingkou irrigation area,Hongqi irrigation areaas typical irrigation areas.Due to the maximum shear stress and the calculation of frost heaving amount need to select parameters related to the soil in this article,the soil samples in typical irrigation areas were collected,and the properties of soil were named through specific gravity test,grain analysis test and water ratio limit test.Then the typical section form of lining canal in Liaoning province coastal irrigation area is selected that the floor width is 0.8m,the channel depth is 0.8m,and the slope is 1:1.25.According to the mathematical model of trapezoidal concrete lining canal established by Wang Zhengzhong and the calculation of crack resistance condition formula ?0/Ec??t,we can conclude that using C25 concrete and 10cm thick lining plate can meet the requirement of cracking resistance.Also,according to the frost heaving amount formula h=f Zd derived by Wang Xiyao et al from the Water Conservancy Research Institute of Liaoning Province,and the insulation thickness of benzene board formula?x=?w??x(R0-?c/?c),it is suitable to use 10cm thick benzene plate structure in lining channel of coastal irrigation area in Liaoning Province,which can meet the requirement of anti-frost heaving.Finally,in order to verify reasonableness of the calculation above,taking Habin irrigation area as Pilot project,12 kinds of lining with different structures are established,and soil temperature,frost heaving depth and frost heaving amount of foundation soil of 40cm,80cm deep canal foundation soil are measured between December 2015 and March 2016.Through analysis and comparison,it is found that when cross section is 0.8m wide,channel depth is 0.8m,and slope is 1:1.25 in lining channel,C25 concrete,10cm thick plate and 10cm thick benzene plate structure can be used to solve the problem effectively of lining frost heaving in the irrigation areas of Liaoning Province.