Experimental Study On Canal Lining And Seepage In Irrigation Area Of Yellow River In Ningxia

Ningxia is one of the places where brilliant Chinese civilization originated,which is the main point of the ancient silk road and is also the“Southern Frontier" of“One Belt And One Road.”.The area here with long history is one of the oldest irrigation areas in China.After the establishment of the new China,some water conservancy projects such as the river dredging and the lining concrete engineering used to prevent the seepage is carried out.However,with the gradual growth of the lining distance and the expanded area,some problems gradually raised:the Nngxia irrigation area was located in the highlands,and part of the groundwater was higher than the bottom of the canal and spread to the below of the lining.In winter,the water in the lining freezes with temperature below zero and produces certain pressure,causing break of the lining and influence of the channels safe operation.Therefore,it is necessary to make seam on the lining to eliminate the damage caused by the pressure.However,too much seam can cause increasing water leakage and lose the use of the lining itself.For the contradiction,the thesis will make a research for the relationship between the mass of inhibitor and the factors such as the width of the lining seam,the place where to make seam,the width of the channel and the foundation condition so as to provide the technical support for the lining works.So,let’s Begin the thesis as following:Firstly,the percolation coefficient and the density are determined by the typical channel section of Ningxia irrigation area in order to make a preliminary judgment of the composition and nature of the different canal base soil.Then,the typical soil will be examined in the laboratory detailedly to determine the standards such as the grain composition,density,moisture and the and liquid limit of soil,as well as other physical properties finally to make preparation for the next model test.Secondly,the model box is designed according to the geometric similarity,motion similarity and dynamic similarity model,which is made by a certain proportion of the geological entity of the irrigation areas.Not only the boundary conditions of the channel are completely identical,abut also the simulation can be used to reproduce the real process of nature seepage.Then the relationship between the experiment results and the actual seepage quantity of the prototype can be analyzed,the formula for the conversion of the experimental model and the prototype leakage is given.Finally,the thesis stimulates the different form of the channel lining,foundation conditions and leakage process of different lining types so as to analyze the relationship between it and the leakage,Meanwhile to calculate the efficiency of routing in different channels,lining water-saving coefficient and lining water-saving amount.What’s more,the influence law of the data analysis lining to the type on the leakage of various lining channels should be collected,and the effect of the anti-seepage of various lining types should be analyzed.The thesis stimulates the leakage process of different lining types and calculates the efficiency of routing in different channels lining water-saving coefficient,which provides the data support for the selection of the leakage lining scheme in the irrigation area of Ningxia with great practical significance.