Analysis on pre-camber forms of high-speed EMS maglev bridge

To investigate the appropriate pre-camber of high-speed electromagnetic suspension （EMS） maglev bridges， the deformations of single-span guideway， double-span guideway and 40+60+40 m continuous girder under the action of train static load，temperature， shrinkage and creep are calculated， which are combined into 12 kinds of pre-camber curves. The influence of train speed， rated suspension clearance， temperature， shrinkage and creep， bridge structure on the performance of maglev train is discussed by means of train-bridge coupling vibration analysis method. With the driving safety and ride comfort index， the proper precamber form of the high-speed maglev bridge is analyzed. The results show that， the comfort and safety indexes of the high-speed maglev train on the single-span guideway are better， when the train speed is smaller， the rated suspension gap is larger， and the bridge deformation under train static load， temperature load， shrinkage and creep is opposite and close to the pre-camber. In each pre-arch condition， the train has the best driving performance on the double-span guideway， and the comfort of the train on the single-span guideway is better than that on the 40+60+40 m continuous girder， while the driving safety is worse. Based on the results of running performance， it is suggested that the pre-camber is not necessary for the double-span guideway， and the pre-camber for the single-span guideway and 40+60+40 m continuous beam can be set to 0.5 times and 1 time of train static load.