Design And Data Processing Of Re - Testing Scheme For Precision Engineering Planar Control Network

Subway construction required a longer duration from survey and design,construction to operation and maintenance procedures, under the influence of theexternal environment conditions, it may cause the displacement of the control pointsof subway construction and thus bring different degrees of impact to the metro lineproject construction and operational maintenance and repair observations, resulting inunnecessary losses. Therefore, in order to ensure the quality and a smooth finish ofthe subway construction, retest control network is a must.The paper is based on GPS positioning technique in the BT project ofshenzhen metro line9heads of GPS control net survey engineering applicationexamples, data processing and analysis research, analysis the existing known pointscompatibility、control point stability problem of the retest procedure, to study thetechnology and methods to solve these problems, making research on the technicalmethods to solve these problems.the main research results of the paper are as follows:（1）By the comprehensive research and discussion of the subway controlnetwork reiteration principles, thus design a set of feasible retest scheme.（2）Comprehensive analysis the accuracy and quality of the GPS retest data,this provides a data base for the compatibility analysis of the high point, stabilityanalysis of the control point, making the conclusions of this paper more authenticityand persuasiveness.（3）Discusses the measured baseline comparison, the scale parameter analysis,check-point method, with a combined route coordinates and variance of unit weightoff legitimate hypothesis test to make compatibility analysis for the starting point ofthe retest control network, and use the practical project of Shenzhen Metro Line9asa case study to determine whether the accuracy of the starting point is qualified,demonstrate check-point method is a high efficiency, reliable and practical method inpractical engineering of Checking the compatibility of a known point.（4）discussed two methods of the control points Stability analysis, combinedwith case analysis, the results show that comparison method of the point middle errorwith the Coordinate value difference of retest and original measured is suitable forthis type of project construction.（5）Studied the influence degree the point error of the retest results making tothe subway tunnel lateral error, guide the subway tunnel construction.This paper discusses the application of the GPS positioning technology in Shenzhen Metro Line9Primary GPS Control Network BT project engineeringprojects retest, solved the known points within the network stability, stability ofcontrol points and other practical problems, to ensure project quality, and provide areference for such projects and has a certain reference value.