Analysis And Experiment On Pounding Responses Of Simple-Supported Bridges Under Earthquake Excitation

The pounding between adjacent frames because of large displacement of girders may cause great damage of isolated bridge or even lead to collapse of superstructures. The pounding between components of bridge has significant influences on bridge performance under earthquake, but, pounding effects of components of bridge under earthquake is not considered in the codes. Hence, in order to prevent the damage because of pounding between components of bridge, the pounding between components of bridge should be roundly analyzed.The analysis and experiment on pounding responses of simple-supported bridges under earthquake excitation are systematically performed in this thesis. The main researches are involved as follows:(1) The thesis study the influence factors of pounding including foundation, supports and the stiffness of bridge's piers, and the influence of pounding of the seismic behavior of simple-supported bridges from two-dimensional time-history analysis of finite element model.(2) The thesis research the influence factors of pounding including gap, mass ratio of adjacent girders and supports, influence of pounding of the seismic behavior of simple-supported bridges and measures to prevent the pounding from the experiment of shaking table.Some conclusions are given as follows:(1) Pounding of simple-supported bridges is caused by the coalition of many factors, for example gap, and bridge structure vibration characteristic and earthquake characteristic. The gap is larger and the times of pounding are less, but the max pounding force can not be confirmed only from gap. The greater pounding response can be obtained for higher mass ratio of adjacent girders. The most disadvantageous pounding response occurs between longer girder and bridge abutment. The foundation affects the pounding force obviously.(2) The bridge's piers is higher, the shear force of piers is greater during pounding. It is not simply considered pounding is advantage or disadvantage in seismic behavior of bridges' piers. The earthquake and construct is different, and the effect of the bridge's piers is different. The damp of the impact element affects the pounding force obviously, but the affects the shear force of the piers not obviously.(3) The Supports' energy dissipation and damper reduced the pounding force or prevent the pounding.