Study On 3d Seismic Pounding Effect Of High-Pier Bridge Based On OpenSees

Bridge damages in recent years show that under strong ground motion excitations, the phenomenon of seismic collision damage of high-pier bridge is very significant. it is essential to study the seismic collision of high-pier bridge and the measures of anti-seismic collision beacause of complex seismic collision mechanism and causing deck beams end cracked, abutment cracked or block cracked,bearing damage or failure,bent falling caused by seismic collision.This article analyzes the seismic collision effects of high-pier bridge in detail based on summarizing the extensive literature,and discusses the measures of anti-earthquake impact preliminarily. The main contents are as follows:1 Realization and verification of 3D contact friction model. Programing 3D contact friction model based on OpenSees redevelopment function and doing the numerical verification of the model by simple examples.2 Study of 3D seismic collision effects of the high-pier bridge.Building 3D nonlinear finite element model of a high-pier bridge based on OpenSees to do the analysis of seismic collision effects of the high-pier bridge under uniform excitation and multi-excitation considering the effect of traveling wave.And analyzing the reaction rule under different ground motions, and focusing on the differences of the effects of seismic pounding between uniform excitation and multi-excitation considering the effect of traveling wave.The results show that the seismic responses of high-pier bridge are closely related with its inherent dynamic characteristics and the spectral characteristics of ground motion and closer to the natural cycle of the bridge the main periods of ground motion is,greater the bridge collision response; traveling wave effect amplifies seismic pounding response, while the end of piers are adversely affected, exacerbating the damage. Although whether or not the traveling wave effect is harmful to the bearing, the traveling wave effect has obvious influences to bearing. Therefore, in the analysis of bridge seismic collision response it is necessary to consider traveling wave effect.3 Discussing Anti-seismic pounding of the bridge with high-piers preliminarily.Under multi-excitation considering the trveling wave effect, doing comparative analysis of the seismic response of the bridge with high-pier between with and witnout the anti-collision damper which is set on pounding location.The results show that setting anti-collision damper can be effective in preventing collisions between deck beams and between deck beam and block,and the displacements of the bridge piers is limited, internal forces of piers'ends greatly reduced,reducing the damage to piers,which will help to improve the overall seismic performance; but setting collision damper would also adversely affect the bridge with high-pier, increasing the possibility of damage to the deck beams, uncertainty of bearing reaction.