The Design Of Configuration And Precision Of Control Networks For Ballastless Track

The basic requirements of designing high-speed railway are to ensure the train's safe,reliable and comfortable operation based on designed speed.Some new problems with the construction of high-speed railway will be brought out by the high speed,which are the inner geometry size and the outer geometrical size with ballastless track of passenger dedicated railway connected with the Surveying and Mapping Science.Tradional ways of surveying cann't already satisfy the precise demand of the ballastless track of passenger dedicated railway's survey precision.So,we should found a suit of favorable survey system and the precise control networks.In order to improve the efficiency and save expenditure,the multilevel control networks should be adopted.Because the high precision of control points is needed in tracklaying,the points position errors of control networks should take the initial data errors into account.This paper research the configuration and observation precision standards of CP0 and CPâ…¢control networks across-the-board, illuminate the model of precision evaluation that consider the impact of initial data erros detailedly,then compare the adjustment methods of CPâ… control networks base on this model.If take the CPâ… control networks as the basic control networks of all levels and the CPâ… control networks adopt the methods of integrate adjustment,which would result in very low precision in middle position of control networks because of errors cumulation,at last impact the track linetype.The control networks CPâ… may be divided into some sub-networks by adding frame control networks CP0,and the CPâ… control networks adopt the fixed data adjustment,which could enhance the positional precision of all control networks obviously.The CPâ…¢control networks is the benchmark of paving ballastless track and the precision of CPâ…¢is the key technology of paving ballastless track,due to the impact of initial data errors of CPâ… and CPâ…¡control networks,the accuracy analysis for CPâ…¢should take the initial data errors of high-level control networks into account,this paper do configuration test of CPâ…¢traverse according to three schemes,analyse results of the tests,acquire the optimal configuration of connecting for CPâ…¢control networks.The experimental results show that CP0 may be taken as the first level control networks for ballastless track,the CPâ… control networks is connected to CP0 with fixed data adjustment,and the positional precision of CPâ… control networks would be 3 times than without CP0; If the CPâ…¢traverse connected to the CPâ… and CPâ…¡control networks synchronously,the criterion of track linetype would be overstep at the junction between two CPâ…¢control networks.These conclusions would be the effective supplement to current surveying criterion,and helpful for building ballastless track.