A Study On Survey Technique In Base-Piles Control Network For Ballastless Track

The China railroading has run to a leap-forward development stage, the high-speed railway and the passenger dedicated line are constructing rapidly. Therefore, the standard of survey technique has to satisfy the request of design, construction and maintenance about the 160-350 km/h railway. Some new problems with the construction of high-speed railway will be brought out by the high speed running of a train. The ballastless track has quite a number of virtues comparing with the ballast track. Track evenness and straightness with high precision is one of the most extrusive points about ballastless track of passenger dedicated railway, which would restrict directly the train's speed. The theory and practice indicate that the control and construct of track evenness and straightness with high precision have become one of some key techniques which decided success or failure about the high-speed railway's construction. Therefor,in order to satisfy this request, we must build precise control networks for ballastless track.The control network for ballastless track is the controls benchmark of the paving ballastless track, the precise of which is the key technique. The control networks of foundation pile are measured by the 5-class traverse according to Provisional Criterion of Ballastless Track Railway Engineering Surveying for Passenger Dedicated Line. There are three forms for control networks of foundation pile, such as the traverse, the side-angle resection depending on traverse and simple side-angle resection. By the tests of some measured data and theoretical analysis of initial data errors, some comparisons among these surveying forms about the control networks of foundation pile are studied firstly. And then, by some simulation tests, some comparisons between the three unied shelves (TUS) and the free stationing which based on the side-angle resection are studied too. Some criterions of surveying precisions are obtained also by some simulation tests finally.The experimental conclusion shows that side-angle resection depended on densification of travese would obtain higher relative precision and finer smoothness than the restricted traverse. The TUS for the side-angle resection would obtain finer smoothness than the free stationing. Some criterions of surveying precisions what can satisfy the requests of the high-speed railway criterion of Germany are obtained also by analyzed and epurated some results of simulation tests. These conclusions should be helpfully to build construction control networks for ballast less track of passenger dedicated railway.