Analysis of Train Derailment and Limit Value of Lateral Rigidity for Deck Steel Plate Girder Bridge

Several derailment accidents of freight train have happened on deck steel plate girder bridges. The width-to-span ratios of these bridges all satisfy the limit value of lateral rigidity ([B/L]= 1/20) given by railway bridge design code. The condition of track on the bridge also satisfies corresponding code. The study on derailment accident and lateral rigidity for deck steel plate girder bridges by the way of theory analysis is needed urgently. In this paper, the theory of energy random analysis for train derailment is used to analyze the derailment cases on three deck steel plate girder bridges. The calculated results correspond to the actually occurring accident, which manifests that the theory of derailment analysis above is effective for the analysis of train derailment on bridges further. By investigating the property of lateral rigidity of the bridges on which derailment ever happened, it can be found that the scarcity of bridge lateral rigidity is a dominant cause resulting in derailment on bridges and derailment accidents can not be prevented with the lateral rigidity limit value ([B/L] = 1/20)for deck steel plate girder bridges. To prevent derailment on deck steel plate girder bridges to be designed and built, new limit value of bridge lateral rigidity for derailment prevention needs to be established. In this paper, a new method to analyze the limit value of bridge lateral rigidity for derailment prevention is presented on the basis of the theory of energy random analysis for train derailment. By this method, the lateral rigidity limit value of 32 to and 40 m long deck steel plate girder bridges is established.