Nonlinear Seismic Responses Research Of Curved Girder Bridge

With the vigorous development of transportation in our country, high grade highways, city overpasses and viaducts are increasing. The curved girder bridge has been widely used because of its excellent adaptability and graceful lines, however, due to its special mechanical properties, curved girder bridges tend to be more seriously damaged when the earthquake struck. Studying the nonlinear behavior of curved girder bridges in earthquake especially severe earthquake has vital significance to its anti-seismic.Taking a prestressed concrete continuous curved bridge in a light rail of ruanjianyuan road to guoshui road as engineering background, nonlinear dynamic time history method is used, the thesis research content as follows:1) Expounding the mechanical characteristics and calculation theory of curved girder bridge, introducing the research status of the curved girder bridges anti-seismic, main methods of earthquake resistance and the material constitutive model, which laid a foundation for the seismic analysis of curved girder bridges.2) Respectively building different curvature radius, different height of pier and different ratio of side span and cross through finite element software Midas/civil, analysis these factors to the influence of curved girder transverse and radial basic vibration period.3)Nonlinear time history analysis and finite element model with different radius of curvature in single direction earthquake excitation are used to research the radius of curvature on internal forces of the piers two major axis coupling effect. The radial and tangential directions of bending moment-curvature curve are used to evaluate the plastic state of No.3 pier section under seismic action.4)Through 0°?360° rotating input seismic action to different radius of curvature model, we study the seismic reaction law of curved girder bridge under the influence of radius of curvature and seismic input angle. Make sure the most unfavorable input angle of different radius of curvature. We also compared the most unfavorable input angle with the two major axis directions of No.3 pier.5) Studying the law of curved girder bridge seismic response with different nonlinear degree by different earthquake intensity of nonlinear time history analysis on the same radius of curvature finite element model.6) Nonlinear time history analysis of different pier height finite element model under different ground motion on single earthquake excitation is used to study the seismic response of the curved girder under different bridge pier height.7) Nonlinear time history analysis of different ratio of side span and cross finite element model under different ground motion on single earthquake excitation is used to study internal forces two major axis coupling effect and seismic responses of the curved girder under different ratio of side span and cross.8) Nonlinear time history analysis of finite element model on single earthquake excitation is used to study seismic responses of the curved girder under LRB.