Study On Problems Of The High-speed Railway Construction Control Network

The line control network (control point Ⅱ) plays the role of the construction planecontrol in high-speed railway construction. The retest work generally finished by differenttenders, and may be responsible by different measurement teams. So there will be somemeasurement dates which can not be strictly connector. The retest overrun of high-speedrailway construction control network within the construction unit tenders will cause deviationof High-speed rail line project engineering construction stakeout, and may eventually lead tothe entire line can not be smoothly connected.There are two major kids of correction about the construction stakeout deviation in thispaper. First of all, start from retest of the construction control network. Analysis the impact ofthe control retest accuracy, what caused by the measurement reference ellipsoid imputingerror and planar projection distortion error and so on. Improve the reliability of the results ofthe retest through a series of error correction calculation. Secondly, start from the constructionstakeout. Analysis types of the deviation that appear from High-speed rail line projectengineering construction stakeout, design the appropriate the loft correction program,calculation of the loft to correct coordinates. Correct deviations In the process of constructionstakeout directly. Study found that, using correction calculation, simulation satisfaction etccan effectively reduce the affect brought by error. But the using of coordinate are also limited,the error will come back when overrun once again. Correcting deviations In the process ofconstruction stakeout is a mechanical correction. If the responsible units agree with thismethod, it can make us achieve the desired objective.The vertical control network measurement of high-speed railway major include theheight measurement of Line benchmarks and orbit control network (control point Ⅲ).The paper research on some methods which consider in the height measurement of Linebenchmarks and encryption elevation points, investigate the methods how to useTrigonometric leveling instead of second leveling by Total Station, and application of GPSheight measurement. Studies have shown that the Total Station or prism should be modified in the measurement when we use trigonometric leveling instead of second leveling. In thisway, although the accuracy of the measurement results can be achieved in theory requires, tobe widely applied to the instance still need further study. In order to explain how to use GPSHeight measurement method retest the vertical control points of high-speed railway whichcrossing river, the author deduced height difference calculation formula of elevation pointsbetween both sides.