Research On The Stability Analysis Method And Application Of Railway Survey Control Network

In order to ensure that the railway survey control network can provide high-precision coordinate benchmarks,it is necessary to retest it regularly and irregularly,and to analyze the stability of the control points.Taking the high-speed rail CPII control network based on the GNSS measurement method as an example,the study found that the existing high-speed rail CPII control network retest stability analysis method has unstable CPII control network starting point,unreasonable stability analysis tolerance index,and possible " The phenomenon of “discarding the truth” and other issues.In response to the above-mentioned problems,this paper studies the existing high-speed rail CPII control network retest stability analysis method.The main research content and conclusions are as follows:(1)Aiming at the problem that the starting point of the existing CPII control network retest may be unstable,the stability analysis method of the CPII retest network starting point based on the original retest distance method is studied.For the starting point judged to be unstable,this paper studies the interpolation method and the substitution method to update the coordinates of the starting point of the unstable CPII re-measurement network.Combined with the experimental data,the feasibility of the above method proposed in this paper is verified.(2)Introduced the origin of the CPII control network retest stability analysis tolerance index in the existing specifications,and pointed out its lack of theoretical support.Then this paper theoretically derives that the relative accuracy tolerance threshold of the coordinate difference between CPII adjacent control points should be1/40 000 when the point spacing is only 300m?600m,and the original and re-measured coordinates of CPII control points are derived.The component difference tolerance threshold should be 6mm.Combined with the experimental data,the correctness of the tolerance index of the CPII control network retest stability analysis studied in this paper is verified.(3)Aiming at the problem of "discarding truth" in the CPII control network retest stability analysis method in the existing specifications,this paper optimizes the existing methods and develops the high-speed rail CPI and CPII control network repetitions based on the optimized method.Test stability analysis data processing software(the high-speed rail CPI,CPII control network retest stability analysis method is the same,only the threshold of the difference index is different).Combined with the experimental data,it is verified that the optimized high-speed rail CPII control network retest stability analysis method will not have the problem of "discarding truth",and the correctness of the high-speed rail CPI and CPII control network retest stability analysis software developed in this paper.(4)In addition,due to the need to re-measure the control network at all levels during the construction and operation management of the high-speed railway,a large amount of control network plane coordinates and elevation data will be obtained.In order to manage these data more conveniently,this paper developed Railway survey control network data management system.Combined with the experimental data,it is verified that the high-speed railway survey control network data management system developed in this paper can efficiently and flexibly manage the plane coordinates and elevation data of the control network at all levels.