Research On High-speed Railway CPâ…¢ Horizontal Control Network Adjustment Method And Program Designing

Abstract:In recent years, ballastless track structure of the High speed railway construction has been widely used in China. The CPIII net of high speed railway is the control baseline of laying ballastless track and maintenance of railway. In order to ensure the high smoothness of ballastless track, it is necessary to have not only a reasonable network of control net and precise system of measurement, but also an efficient precise adjustment of the data to guarantee the precision of coordinate.In this thesis, based on the measured data of ballastless track, the primary investigation objectives are the gross error detection methods of measurement data in horizontal control network of high speed railway, the precision index of CPIII net, the method of free net adjustment, constraint net adjustment and the corresponding design of adjustment program for control net. Three kinds of optimization design of CPâ…¢ control network such as the adjustment datum, the strength of net form and observation accuracy are analyzed. The following aspects are implemented:(1) Based on the horizontal control network of CPâ…¢ and adjustment theory, the method for determining the number of independent closed loop and searching the closed loop in the CPâ…¢ network was proposed. Introduced the mathematical model and precision evaluation formula of CPIII network and it will be the theoretical foundation for studying adjustment method.(2) Three kinds of calculation method for approximate coordinates under different reference coordinate system were adopted to analyze the effect of free-net adjustment that approximate coordinates can influence. The influence on the result of free net adjustment under different adjustment base was analyzed.(3) The method of Helmert variance component estimation and baarda data snooping were used to analyze the influence of adjustment result that function model and stochastic model errors in the adjustment model can effect. (4) The language of VC++and Matlab were combined to project the adjustment program for horizontal control network of CPIII. The result of other existing adjustment software was compared to verify the practical assessment of the program.