VERTICAL CONTROL SURVEYING AND PRECISION ANALYSIS FOR BALLASTLESS TRACK OF HIGH-SPEED RAILWAY

摘要

With the large scale construction of high-speed railway in China, the ballastless track has got rapid development and extensive application.Ballastless track is directly on a solid substrate pouring of concrete layer foundation under the rail.It has an overall strong, longitudinal and lateral stability, and is easy to keep the geometric shape and position of the track.Establishing CPⅢ control network with high precision and reliability is the basics of maintaining smoothness and comfort of high-speed railway ballastless track.Free station side-angle resection is used to build CPⅢ plane control network, while the elevation control is build by precise leveling.According to the new passenger rail lines code for engineering survey, CPⅢ points must joint to the ground known level point lessen distance 2 km.Because the bridge height is usually 10 meters higher than the ground, it is very difficult to transmit the elevation of the bench mark on the ground to the bridge by geometric leveling.In this paper, a method with trigonometric leveling is introduced, which with no measurement of instrument and target height, and a Z-shaped observing-routine was proposed to measure the elevation of CPⅢ network points.Beijing-Shanghai intercity project survey results indicate that the program measurement method is reasonable.