Study of Vertical Stiffness Limit for Main Bridge of Shanghai Changjiang River Bridge

The highway lanes and light rail lines of Shanghai Changjiang River Bridge are arranged on the same deck and the highway lanes are obviously more than the light rail lines.Hence,the way of how to rationally determine the vertical stiffness design value becomes one of the key techniques for construction of the Bridge.In this paper,the ability of the train riding through the Bridge is used as the control factor.Firstly,by using the conventional method,the static deformation curves of the bridge deflection caused by the live load are regarded as the unevenness excitation at the time the train rides through and the minimum vertical stiffness limit value for the bridge design that can satisfy the rideability of the train is preliminarily determined.Secondly,the dynamic responses of the vehicles(train) and the bridge are calculated by using the analysis methods of the coupling vibration among the highway vehicles,light rail train and the bridge,the calculation differences of the two kinds of the methods are analyzed,the minimum vertical stiffness limit value as mentioned is modified and finally,the minimum design value of the vertical stiffness of the Bridge is given.