Rehabilitation Design And Process Improvement Of Stainless Steel Lining Of Water Supply Pipeline

Stainless steel lining repair technology refers to mechanically pulling the manufactured stainless steel sheet into the underground pipeline,and fixing it on the inner wall of the original pipeline by manual welding or mechanical support,so that the inner lining can be closely attached to the original pipeline.Trenchless pipeline repair technology to improve the water quality of the original pipeline,increase the flow capacity of the pipeline,and increase the semi-structural strength.The research content of this paper is mainly divided into four aspects: optimization and improvement of buckling failure model of stainless steel lining,research on improvement of repair process of stainless steel lining,research on residual strength of original pipeline after corrosion,and research on strength of composite pipe after stainless steel lining repair.The research work carried out in this article and the research results obtained mainly include the following aspects:(1)The domestic and foreign theoretical specifications,scope of application,process flow,key technology and main problems of stainless steel lining repair are reviewed in detail;the buckling failure model of the stainless steel lining repair process is analyzed.Pointed out the limitations of the Glock formula.The difference between the mechanical properties of the weld and the base metal is studied.On the basis of the Glock formula,using the principle of minimum potential energy,considering the strengthening effect of the weld and the block welding process of the inner lining,a new buckling failure model that is more suitable for the repairing method of the stainless steel inner lining is deduced.The calculation results using the Abaqus simulation software are not much different from the theoretical calculations;(2)Analyzed the construction process,existing advantages and disadvantages of the currently used stainless steel lining repair technology-folding-expansion method and block welding method.Creatively proposed a new repair method of block spiral welding,and analyzed the model,construction process and advantages of the new method in detail.Afterwards,the Abaqus numerical simulation software was used to simulate and analyze the maximum pressure that the inner lining can withstand when the shape and material parameters are consistent.The analysis of numerical simulation results shows that the new construction method is more effective.(3)Analyzed the corrosion problems existing in the stainless steel lining repair process,the causes of corrosion,the principle of electrochemical corrosion,and the calculation of the remaining strength after the original pipeline is damaged by corrosion;(4)Based on the new calculation model of critical buckling strength of stainless steel lining and the calculation formula of residual strength after corrosion of outer pipe,the calculation formula of composite pipe strength suitable for repair of stainless steel lining is deduced.The formula is to add the residual strength of the outer pipe after corrosion and the critical buckling failure strength of the stainless steel lining,and the value obtained by adding the two is used as the strength of the composite pipe after the stainless steel lining method is repaired.After using the calculation example given by Abaqus,the simulation result is not much different from the calculation result of the formula.