Study On Layered Life Of Concrete Lining Channels

In response to the requirement of sustainable development in today’s society,in the aspect of channel frost heave prevention,not only the durability factors such as frost resistance and impermeability of lining,but also the long-term interaction between lining and environment should be considered.The study of life span and layered life of large-scale water conservancy projects and road and bridge projects has become more and more mature.In contrast,the study of small-scale water conservancy projects such as canal lining only focuses on short-term mechanical behavior.However,canal lining plays an important role in agricultural irrigation and drainage,urban water supply and so on.Therefore,it is necessary to study the durability and green life of canal lining.Based on the previous research results of Engineering life,this paper adopts the layered life method to study the concrete channel lining.Layered life design refers to dividing the whole life design into six levels: safety,reliability,durability,economy,natural environment,social environment and ecological environment.In this paper,the life design of the first three layers is called traditional life design,and the last three layers are called green life design.The main research work is as follows:(1)Discusses the meaning of concrete layered life and the interrelation between different layers.Based on the current research methods and results of canal lining,the methods and steps of layered life research of concrete canal lining are put forward in view of the existing problems.(2)The traditional life study,which satisfies the safety and reliability requirements by calculating the reinforcement in the limit state,also provides material parameters for the finite element analysis of durability;calculates the frost heave displacement and stress changes of the lining with different material combinations in the same freezing period by using ANSYS,and the frost heave displacement and stress changes of the lining with the same material in different freezing periods,and obtains the damage position of the canal lining.Protective measures should be taken at 1/2-2/3 of the canal top.Economy is the sum of initial cost and future cost,which can guarantee safety,reliability and durability.(3)Study on green life,use analytic hierarchy process to assign the scheme,and then select the optimal scheme.In the natural environment,social environment and ecological environment,there are many impact indicators,and there may be overlapping parts among them.Therefore,the principal component analysis method is used to select the main impact indicators,and then the selected indicators are used as the middle level of the analytic hierarchy process to determine the scoring matrix by expert scoring,and then the consistency test is carried out to ensure that the assignment meets the requirements of the analytic hierarchy process.Finally,the weight of each scheme is calculated,and the advantages and disadvantages of each scheme are analyzed.(4)Through analysis and calculation,the cumulative increase of maximum frost heave displacement and stress of C25HRB335 lining in three freezing periods is 4.71% and 26.13%,which is less than the change of C20HRB335 lining,and the difference between the change of C20HRB400 lining and that of C25HRB400 lining is small.The analysis results are in good agreement with the actual situation;the green life weights of C20HRB335 and C25HRB400 lining are 0.271 and 0.357,respectively,and the weight of C25HRB335 lining is 0.365.Among the three schemes,the proportion is the largest.The layered life of the channel lining has certain theoretical and practical value.