Research On Fitting And Optimization Methods Of The Plane And Vertical Section Linear Of Existing Railways Considering Operation And Maintenance Requirements

With the constantly advancement of the socialist modernization in China,passenger and freight traffic of existing railways have been increased rapidly,which puts forward stricter requirements for the maintenance of railway track.Also,with the existing railways under its high loaded operation,its actual linear position have changed a lot compared with the original one.If the original design of railway lines continues to be the evidence of linear correction of the plane and vertical section,it will largely increase the workload largely of the railway correction,and it can’t correct the linear of the existing railway during the operating time.Given the problems above,this thesis conducts a fitting process on the plane and vertical section linear of the existing railways by using measuring instruments,which are used for testing the track smoothness to collect measured 3D coordinate of railway midline,optimizes and calculates the plane and vertical section fitting linear of the railways with combining relevant regulations and the actual need for railway maintenance so as to obtain the optimizing linear of the railways of the plane and vertical section,which have the minimum adjustment and its linear dimension are satisfy with relevant regulations and correct the railway linear through the guideline of optimized linear parameters of the railways of the plane and vertical section.Based on the ideas above,this thesis studies the fitting of the plane and vertical section linear of the existing railways and the relevant calculation of optimality,the main content and conclusion are as follows:Firstly,on the basis of the preliminary identification of the position of the linear boundary feature of the plane and vertical section linear of the existing railway by using the variation of Azimuth difference and the slope difference with equal length and adjacent strings,the fitting method of orthogonal least square has completed the iterative calculation of the plane and vertical section linear of the railways,and obtained the fitting linear which correspond to the measured linear of the track.Secondly,on the basis of the straight line fitting between the front and back of the horizontal curve,a linear plane optimized model is established by taking the minimum track lining value of measured points of track as objective function,and the circular curve radius and the length of transition curve are as optimized parameters.This model obtains the plane optimized linear with the minimum track lining value and satisfies the requirements of the linear parameters by exploring in the interation interval of the specific radius of circularity and the length of transition curve according to a certain stepsize.Thirdly,after completing the optimized calculation of the linear plane for double-track railways,the optimized calculation method of distance between the double-tracking railways is introduced.Fourthly,on the basis of the straight line fitting between the front and back of the vertical curve,a vertical linear optimized model is established by taking the overall weighted track lifting and lowering value of measured points of track as object function,and the length of the minimum slope section of vertical curve and the maximum slope,the maximum slope section difference of the adjacent grade and the minimum radius of vertical curve as the limitation.This model obtains a vertical optimized linear which has the overall weighted minimum of the amount of track lifting and lowering value and satisfies the requirements of the linear parameters by introducing the factors of the overall weighted track lifting and lowering value in the iterative interval of the specific radius of vertical curve according to a certain stepsize.Finally,the linear fitting of the plane and vertical section of existing railways and optimized calculation software are developed by using C# combined with the linear fitting and optimized calculation of the plane and vertical section of railways proposes in this paper.This software is proved to be flexible and accurate in section,fitting and optimized calculation of the plane and vertical section of the existing railways.