Research On The Durability Life Of Foundation Of Transmission Line Tower Under Saline Soil Conditions

With the development of power grid construction, more and more transmission lines went through saline soil. The foundation of transmission line was as an important load bearing part of tower, under the saline soil conditions and the influence of factors such as corrosion and load, the durability life of the foundation usually does not satisfy the requirements for the intended use, and thus durability became failure, which will affect the safety of the transmission line. Considering the problem of the durability of the foundation of transmission line, the research on the prediction of durability life of the foundation was carried out which can provide the theory method and the basis for the line foundation durable life design.This paper summarized the research status of prediction model of durability life of concrete, and then based on mechanism of chloride ion diffusion, the influences of many factors were taken into account, modified chloride ion diffusion equation was given, and on this basis, established the prediction model of durability life of the foundation of transmission line. Using finite element method to calculation numerical simulation of chloride ion of foundation interior, obtained the chloride ion concentration at the surface of the steel bar, and compared with the predictions of the analytical solution of the error function to verify the feasibility of the finite element method. Finally, choosing the western saline soil area UHV DC project tower foundation, using the finite element method to predict durability life, and analyzed cement, fly ash and slag preparation parameters, temperature, humidity and other environmental parameters to effect the durability life of the foundation of transmission line, For prediction of the durability life of the foundation of transmission line under saline soil conditions providing a theoretical basis.