Research And Application Of Method For Retesting CPⅢ Control Network During Operation And Maintenance Stages Of Ballastless Track

High speed railway in China has entered a period of comprehensive operation of ballastless track of high-speed railway construction, with its high stability, high comfort and features easy to repair, has been widely used. High speed train put forward higher requirement for the smoothness of the track, and the smoothness of the track by track geometry determined, CPIII measurement and control network to provide basis for the ride comfort test track control, complex measurement methods, the accuracy of the data will have an impact on the track. A review of selected methods of survey control network for CPIII and observational data precision will directly affect the ballastless track. As the control datum for checking and adjusting the CPIII,during the operation and maintenance stages the railway track of high-speed railway needs to be retested regularly to ensure railway ride, the CPIII track control network should be done within four hours of maintenance window time at night. Up to the retesting method stipulated in the current code, the CPIII track control network has to be co retested with the control points of the higher rank section by section, it has been existence heavy workload and low efficiency.So it is necessary to develop a new method to enhance the efficiency of CPIII retesting.In order to provide theoretical foundation for the research content, this paper firstly introduces the significance of unified railway engineering measurement system, the CPIII track control network and elevation control network of CPIII two part of theoretical research.Including the control point selection, network of CPIII control point layout and CPIII control data accuracy index.In view of the CPIII control network of measuring of Harbin Dalian passenger dedicated line, the research of CPIII control network observation method, principle and process of data processing, the CPIII plane control network observation, using a unique free station linear angular intersection, by instrument automatic search target, aiming the target, reading and recording the original observation data, elevation control network using CPIII loop measurement method of observation; CPIII control network surveying control network needs superior CPI, CPII network, encryption of CPII network using GPS.According to the CPIII control net model, put forward the optimization scheme of CPIII control network retest method, the geometric model between CPIII and the transverse and longitudinal chord to test the stability of CPIII control net, wherein the geometric relationship between adjacent point judgment by transverse and longitudinal chord length relationship between CPIII. Covariance propagation rate using MATLAB programming to simplify data processing based on chord error, come in, through the contrast measure and the original measurement error to judge the stability of CPIII points. According to the "norms" of high-speed railway project is measured chord length limit of reliability difference error as the judgment standard to judge the results of data processing, explain the relation between CPIII net with adjacent point several to detect CPIII point stability is significant.