Research And Optimization Design Of Seepage Proof Water Conveyance Canal In Soda Saline Alkali Land

Water and soil resources are the foundation of human survival and development,and soil salinization is a global ecological problem.There is a shortage of land resources and water resources in my country,so it is of great significance to rationally develop and utilize soda-alkali land in Northeast China and improve the utilization rate of land resources and water resources for national food security and social stability.After the improvement of soda saline-alkali land in Northeast China,it is mainly a rice planting area.The traditional water delivery methods are mainly earth canals and concrete canals.The shape and structural parameters of the canal have a great influence on the water utilization rate of the canal.In Northeast China,the winter is long and cold,and the phenomenon of channel frost heave damage is common,which not only shortens the service life of the channel,but also increases the maintenance cost.Therefore,the channel material selection has a more significant impact on the channel water utilization rate.This paper relies on the 800hm~2severe saline-alkali land improvement project undertaken by Zhongke Baiaogelin Agricultural Development Co.,Ltd.in Sanye Village,Haituo Township,Da’an City,combined with the construction practice of the soda saline-alkali land rice planting project area in Haituo Township,Da’an City,to develop the soda saline-alkali land farmland channel The experimental research of water transmission and anti-seepage technology was carried out,and relevant conclusions were drawn,which provided theoretical analysis and scientific basis for the future FRP channel engineering.The main research contents and conclusions of this paper are as follows:(1)Conduct field seepage testing.The seepage test was carried out on the concrete canal and the glass fiber reinforced plastic canal in the northeast soda saline-alkali land,and the seepage test was carried out through the dynamic water test and the typical hydrostatic test method.The test shows that the water loss and leakage strength of the glass fiber reinforced plastic canal have obvious advantages.The water loss utilization coefficient is reduced by 73.4%,and the leakage strength of the FRP aqueduct is only 1/4 of that of the concrete aqueduct.(2)A comparative analysis of the applicability of the two channels for soda saline-alkali land.Combining the comparative analysis of the salt-alkali resistance,comprehensive investment and other factors of the two channels,it can be seen that the characteristics of the FRP channel are more suitable for the use of soda saline-alkali land.For concrete canals,the difference in the comprehensive investment between the two channels is about 1%.(3)Research and analysis on the simulation analysis of seepage field in two different channels.Numerical models were established for concrete canals and fiberglass canals,and the seepage field analysis results were obtained based on seepage theory,and the actual seepage of the two channels was tested:the relative error between the simulated and measured values of the concrete canal was 1.08%to7.98%,and the average relative error was 4.05%.The relative error of FRP channel is6.07%～21.67%,and the average relative error is 11.6%.The simulated value of the finite element is close to the measured value,and the relative error and NMSE are within the acceptable range.It is feasible to use this model to simulate the seepage of the concrete channel and the glass fiber reinforced plastic channel.In the seepage area of the concrete channel,the seepage flow at the bottom is larger,and the two sides are smaller,and the overall seepage field is relatively large,while the seepage field of the FRP channel is relatively small,indicating that the anti-seepage effect of the FRP channel is significantly better than that of the traditional concrete channel.(4)The optimal design of the section of the U-shaped FRP water channel.The two-stage artificial fish swarm algorithm is used to optimize the design of the channel water depth,arc radius,and camber angle of the straight line.The optimized cross-sectional area and flow velocity are compared with the original design,and the finite element model is numerically simulated and verified by ANSYS software.,the results show that after optimization,the channel section flow error does not exceed0.25%of the design flow,and the area per kilometer is reduced by 2%,and the optimization results are better.To sum up,this paper verified the applicability of the FRP aqueduct in the soda saline-alkali land in Northeast China through the comparison of the field seepage test between the U-shaped FRP canal and the concrete canal in the project test area,as well as the theoretical research and analysis of numerical simulation.The canal is more suitable for the characteristics of soda saline-alkali land,and has obvious advantages in soda saline-alkali land in Northeast China.It provides a new choice for water delivery channels in soda-alkali-alkali land in Northeast China.