Pounding Simulation Analysis On High-speed Railway Simply-supported Bridge Under Earthquake Based On LS-DYNA

In a intense earthquake, bearings of the simple supported bridge are easy to be damaged, resulting in poundings of adjacent beams and thereby damages or girder falling. The former studies of the pounding effect are almost focused on elevated bridge of the highway or the city. In recent years, the construction of high-speed rail is increasingly rapid, but there is little research on the pounding problem of the high-speed rail simple supported beam bridge. On the engineering background of the the high-speed rail simple supported beam bridge, A reasonable and accurate finite element model is established for the simulation analysis and the research of pounding effect. The main contents and achievements:(l)With the consideration of bearing failure, nonlinearity of the grider and pier, as well as other factors, a pounding simulation model is established using ANSYS software for the per-treament. And a visual pounding is demonstrated with the use of LS-DYNA for simulation analysis.(2) The result of the pounding simulation show that there will be a greater stress on the pounding surface, and a greater tensile stress on the mid-span, having a negative effect on the beam body; at the same time, the pounding will result in a fluctuation of the reacting force on the foundation.(3) A sensitivity analysis is executed with different parameters including the peak value of acceleration, the adjacent beam spacing and the ratio of adjacent abutment height. The rule of response to beam pounding under different parameters be obtained.(4) the rule of fixed bearing failures is analyzed, and the result shows that the degree of bearing damage is proportional to the rigidity of the bridge substructure. The vertical design force of the bearing can be increased according to the rigidity of the bridge substructure, to remit or avoid bearing damage as well as the pounding occuring.