Three Main Truss Continuous Steel Truss Bridge Axle Vibration Analysis

With the nation's rapid economic development, China's railway construction has gradually entered the era of high-speed railway. The dramatic increase of speed not only shortens the operation time but also increases the bridge vibration, and a lot of dynamic problems needed to resolve come out as well. Against this background, this paper carries out a systemic study focuses on the Dashengguan Nanjing Yangtze River Bridge, which is continuous steel truss bridge with two 2x84m in Beijing-Shanghai high-speed railway. The works completed in this paper are as the following:1. With summary of the history and status quo of researches on train-bridge vibration both at home and abroad, and the evaluation criteria of the train safety and comfort, it offers references for the study of bridge vibration in this paper.2. Perfect analysis models of the vehicle, bridges dynamics are established, and proposed a truss element model which can consider the deformation of the bridge deck. Based on the principle of total potential energy with stationary value in elastic system dynamics and the "set in right position" rule for formulating system matrixes, the corresponding overall vibration equation of the train-continuous steel truss bridge time-dependent system is established.3. Considering three different programs of bridge deck for the continuous steel truss bridge and using truss element introduced in this paper, three different whole-bridge spatial finite element models are established. It also analyzes the characteristics of natural vibration for three programs.4. On the basis of the above analysis models, it detailed calculates the vibration response of train-bridge system of the three programs when trains run through the bridge with the combination of three cases at different speeds, and of which the cases are single line (single line high-speed ICE trains) and three-line (passenger & freight railways: ICE+ double-line freight train, China Star + double line freight train). It also analyzes the influence of the multi-line and train speed to continuous steel truss bridge and makes an evaluation to the transverse and vertical stiffness of the bridge. 5. According to the dynamic performance of the three programs under different work conditions, detailed comparison of the three programs is made in order to get the best option.