Study On Seismic Performance Of Double-deck Continuous Girder Bridge

Because of large-scale urbanization construction and rugged topography,the space demand of the bridge construction is becoming increasingly strained.The double-deck bridge can solve the above problem and has obtained fast development during these recent years.In the same time,it's inevitable to build the double-deck continuous beam on seismic area,however the calculation formula of the earthquake force is only suitable for single-deck bridge in current specifications,and the research on the seismic performance of double-deck continuous beam can be found now.So in this project simulation calculation,member testing and integral model test are adopted to study the seismic designing of the typical double-deck continuous beam,such as the seismic perforce and the seismic control of the bridge,and some useful consults can be got,such as the calculation formula of the pier's internal forces,the control index of the structure strength and the displacement,thus the current seismic design code can be supplemented.Also this project has important theory meaning,practical engineering background and application value on the seismic design of the double-deck continuous beam in china.This article main research content is as follows:Firstly,The self-vibration characteristics of double elevated continuous beam bridge were analyzed.The influence of different bearing arrangements on the vibration mode and frequency were found out.Longitudinal and lateral response spectrum analysis were performed.The dynamic response characteristics of double elevated continuous beam bridge under earthquake were summarized.Then,the relevant structural dynamic theory of seismic excitation time history analysis including the division of the cross section of bridge pier column fiber unit and the establishment of double elevated continuous beam bridge model were introduced.In order to find the characteristics of the dynamic response especially the nonlinear behavior under strong earthquake,the artificial earthquake wave excitation was used in model.Time history analysis was carried out to study the dynamic response characteristics of double elevated continuous beam bridge under rare earthquakes.Finally,the collision problem that might appear in actual earthquake was studied.The results were compared with that of the response without considering the collision.Several mature and reliable measures of isolation were introduced.The effects of seismic isolation were compared and the corresponding suggestions were given.