Seismic Collision Response Analysis And Sensitivity Parameter Study Of Branch Curve Beam Bridges

Curved Bridges play an important role in urban and busy traffic lines.As the main structural form of curved Bridges,branch curved continuous beam Bridges are widely used.To some extent,the branching curve continuous beam bridge can adapt to any terrain and break through the restrictions of all kinds of terrain.It can play its role as much as possible according to the changes of terrain,whether it is to build highways or urban expressways.However,this kind of curved continuous beam bridge also has some disadvantages.Due to the irregular shape of the external structure,the response of the collision is relatively complex under the action of earthquake load,which is easy to cause the destruction of the main beam,bridge pier and other structures.In serious cases,falling beams may even appear.Therefore,it is particularly important to select the design parameters of the branching curve continuous beam bridge so as to avoid the damage caused by the collision in the earthquake to the greatest extent.Therefore,this paper takes the branch curve bridge as the research object,analyzes the collision response and collision mechanism of such Bridges under the action of strong earthquakes,and studies the sensitivity of collision response to its design parameters,in order to provide some references for the seismic mitigation design of branch curve Bridges.The main research results of this paper are as follows:(1)This paper summarizes the current situation of the research,points out the deficiency of the existing research,and puts forward the main points of the research.This paper discusses the phenomenon of bridge collision,failure form,collision theory and its mechanical model,as well as the analysis method of bridge seismic collision response.(2)The 3d solid model of the branch curve beam bridge was established by using the large finite element software Abaqus.The model element and material constitutive are simulated in detail,and the main beam grid is divided into multiple scales,and the collision dynamic response is analyzed by the implicit algorithm.(3)By using the nonlinear dynamic time-history analysis method,the collision force of the section and joints of the branch curve beam bridge is analyzed,and the displacement of the top of the pier,the shear force at the bottom of the pier and the bending moment of the branch curve bridge are analyzed,so as to discuss the collision response of the branch curve beam bridge under the action of earthquake.It is found that the impact stress is different at different time on the same contact section,and the impact has a great influence on the displacement and bending moment of the top of the pier.(4)By changing the design parameters of the bridge,including the distance between expansion joints and the height of bridge piers,the influence of parameter changes on the collision position,collision area and stress peak of the beam section at expansion joints was studied to explore the sensitivity of bridge collision response to design parameters.It is found that when the width of the expansion joint decreases,the collision force decreases,but the collision frequency increases.