Ship-to-bridge Collision Action And Its Effect On The Running Safety Of Train

In order to study the impact caused by ship-bridge collision on the safety of trains moving on the bridges, the pier-water interaction, vessel-bridge collision, and vehicle-bridge interaction were calculated and analyzed in this thesis.Firstly, the pier-water interaction of a pier with arbitrary cross-section was analyzed in the finite element method. A equivalent density coefficient method was then proposed to consider the dynamic behavior of piers with the action of water. The method was validated for a diamond-shaped pylon.Secondly, the techniques of CATIA-HYPERMESH-DYNA were used in the numerical simulation of vessel-bridge collision. By calculating the vessel-bridge collision of a single pylon model and a whole bridge model respectively, the corresponding collision force histories and response histories were obtained with and without considering the pier-water interaction.Finally, the safety indexes of train were calculated for a single train and multi-trains as they passed through a bridge under a ship-to-bridge collision. Parametric analyses were conducted to determine the relation of the safety with the train’s locations, tonnage of ship, and speed of the train.It is shown that the pier-water interaction will reduce the natural vibration frequency of the pier. The vibration models may become divergent or appear in advance because of the pier-water interaction. In addition, the comparative analyses show that the equivalent density coefficient method can effectively replace the finite element method for solving the dynamic problems when the pier-water interaction needs to be considered.The numerical simulations of vessel-bridge collision analysis results show that the maximum value of the collision force tend to be the same value for single pylon model and whole bridge model ship collision, and the pier-water interaction also has little effect on the maximum value of the collision force.The numerical simulations of vessel-bridge collision analysis results also show that the response curves obtained with and without considering the pier-water interaction tend to be the same values during the collision and separate after the ending of the collision. After the collision, the bridge vibrates freely, and the cycle of the damped free vibration increases because of the pier-water interaction.It is shown in the vehicle-bridge interaction analyses that the collision force causes the train’s lateral acceleration, lateral wheelset force, wheel unloading rate, and derailment coefficient increasing significantly. The effect of the collision force on the train’s vertical acceleration is much smaller. If the train is closer to the vessel-bridge collision position, the tonnage of the ship is larger, more dangerous the train will be. The train’s position, the tonnage of the ship and the speed of the train must be taken into considered when determining the most adverse conditions.