Research on the Application of CPⅢ Plane Measurement Method for Outside Skylights of Double Track Freight Railways
In order to solve the problem of the CPⅢ plane control network of the double track freight railway being unable to be measured outside the skylight point during the operation period,a measurement method of bilateral free measuring stations was proposed.By setting up a total station on the shoulders outside the existing railway ballast bed slope toe(gauge),the distance and angle relationship between the total station and the left and right CPⅢ points of the same side,as well as multiple CPⅢ points on the opposite side,were obtained.The results in a corner intersection network contained a large number of direction and distance observations between CPⅢ points and the free measuring stations.The coordinates of CPⅢ points were calculated using the corner network adjustment method.The experiment shows that,the accuracy indicators of the CP Ⅲ plane measurement free network and constrained network adjustment of the bilateral free measurement stations can meet the relevant requirements of the railway engineering measurement specifications.Compared with conventional measurement methods,the accuracy indicators of control network adjustment such as direction adjustment results,distance adjustment results,mean square error of the weakest point position,and relative mean square error of adjacent points have all been improved.The maximum difference in coordinates of CPⅢ point obtained by two measurement methods is-4.1 mm,and the maximum difference in coordinate increments of adjacent points is 2.8 mm,which meets the requirements of railway engineering measurement specifications for CPⅢ control network remeasurement.The research results indicate that the bilateral free station method overcomes the influence of factors such as skylight time limitations and overhead contact line pole obstruction,and can be used for the measurement of the CPⅢ plane control network outside skylights of the double track freight railway.
double track freight railwayskylightCPⅢ plane control networkdual side free station
NETL
NSTL
万方数据
