Influence Study of Track System Restraint on Earthquake Damage of Gravity Pier for High Speed Railway Bridges

摘要

Taking a typical ballastless track continuous beam bridge of China high-speed railway as the actual engineering background, in order to study the seismic damage mechanism of gravity piers are used for the structure under earthquakes.Using incremental dynamic analysis methods, and establishing finite element calculation models with and without consideration of ballastless track system constraints respectively. Selecting ground motion peak acceleration (PGA) as the ground motion intensity indicator, the displacement ductility ratio of the pier top is used as the pier damage indicator, the study on which the mechanism of earthquake damage is carried out, corresponding seismic fragility curves are obtained.The results of the study shows that gravity piers have a relatively small degree of damage under earthquakes, and the overall probability of failure of the bridge is reduced, when consider the constraints of ballastless track systems.When studying the fragility of such bridges, the constraining effects of ballastless track systems should be considered.