Research On Dynamic Characteristic And Seismic Response Of Prestressed Concrete Composite Box Girder With Corrugated Steel Webs

The prestressed concrete composite box-girder bridge with corrugated steel websoriginated in France. And then it has gained extensive research and application in France andJapan. The study of this type of bridges started relatively late in our country, however, itdevelops rapidly. Currently, most of the national and international researchers mainly focus onthe structure of corrugated steel belly bending, torsion, shear and stability. Beams mainly usedin full-scale test and finite element analysis are some simpler structure of simply supportedones or equal section continuous ones. But there are very few researches on long-spanprestressed concrete composite box-girder bridge with corrugated steel webs, especially onthe dynamic characteristics and seismic response.The three dimensional spatial dynamics model was built with midas Civil in thesis. Themechanical properties of the structure on dynamic analysis are studied based on theprestressed concrete composite box-girder bridge with corrugated steel webs underconstruction. The main works involved in this research are as follows.(1) Beam-column element model is adopted to analyze the dynamic characteristics of theentire bridge, and the natural frequencies and vibrational modes of first10models areextracted in modal analysis step. It used finite element programs ANSYS and midas Civil toestablish a spatial solid/shell model and a beam finite element model respectively to analyzethe girder compared to the results of the bridge’s dynamic behavior. It used finite elementprograms ANSYS to establish the finite element model, according to the principle of crosssection of the static bending stiffness equivalent. Of corrugated steel web plate and concreteweb two kinds of section form of the dynamic characteristics of the box girder were analyzed.(2) It analyze the seismic response of the structure by using response spectrum analysismethod and time history analysis method.(3) Nonlinear time history analysis are adopted to study two kinds of schemes ofcommon steel bearings and friction pendulum seismic isolation bearings, and analyze thebridge compared to the results of dynamic characteristics and time history analysis. The influence of the bilateral ground motions and vertical excitation on the friction pendulumseismic isolation bearings are studied by analyzing the change of the friction pendulumseismic isolation bearing’s hysteresis curve.(4) Finally, in order to understand the seismic isolation design more comprehensively, itmade a brief overview and comparison of the specification of seismic isolation design ofsome of the major seismic countries and regions at home and abroad.