Synchronous Swivel Construction Technology Acrossing The Busy Main Railway Lines Of Twin T-shaped Rigid Frame Bridges

Swivel construction means the making(casting or joining together)main body of the bridge In the design axis location and then,turn the Bridges to the original design axis by using the power,It reduces the safety risk,saves construction time and reduces cost input by turning difficult aerial operations(such as over the big river,river,road,railway,gully,etc.)into onshore or ground-based operations.Especially for trans-rail and highway Bridges,it greatly reduces the impact on original traffic.Swivel Construction can be divided into vertical Swivel Construction,horizontal Swivel Construction and Swivel Construction combine vertical with horizontal,horizontal Swivel Construction has the most application,which started in the 1940 s.Scientists in China have made this construction process flourish by constantly and boldly optimizing innovation,Whether it is the span of the bridge,the weight of the body,or the technical difficulty,the new record is constantly refreshed.Since the first introduction of horizontal Swivel Construction in China,which completed the 70 m span arch bridge,in March 1977 in Suining,SichuanTwo important problems must be solved in order for the Swivel Construction to be carried out smoothly: First,we must ensure the smoothness of the swivel’s upper structure during the rotation process.Especially for large cantilevered bridges without cables,we must also ensure that the two ends of the rotation are in equilibrium.But in the operation which from design drawings to the entity structure,it is difficult to ensure the balance of the structure of the swivel that described in theory,due to concrete error,traction cable arrangement error,rotation traction output instability and other factors,and the influence of environmental factors such as temperature and wind stress.Second,how to turn the swivel,generally the upper structure of the bridge body weight is large,it will produce huge friction on the rotating platform construction,improper construction operation will also cause huge inertia moment.How to accurately calculate the frictional resistance and how to set up the traction location reasonably in order to improve the rotational torque is the two key to ensure the smooth implementation of the horizontal Swivel Construction.This paper analyzes and solves these two problems by taking the Longhai railway overpass project on Zhongzhou Avenue in Zhengzhou as an exampleThis paper provides a theoretical basis for the prefabrication of the bridge’s main body,the selection of the rotating traction equipment and the stability control of the Swivel Construction’process by analysing the mechanical parameters of the bridge rotation system which combines the data of design information and transfering bridge weighing and checking the mechanical data provided by the design drawings.With the twin deck bridge’Merge Limits during the construction process and the coincidence of railway clearance range.This paper formulate the synchronous swivel construction process of twin bridge which in Cross Longhai railway overpass construction on Zhongzhou Avenueand and safety protection measures.Also ensure the completion of Swivel Construction of twin deck bridge in a railway construction "skylight",and guarantee the safety of railway transportation.