Structural Analysis Of Continuous Rigid Frame Curved Urban Overpass With Small Radius

Firstly, the derivation of continuous rigid frame curved urban overpass with small radius is analyzed, and the structural characteristics and key design points of this type of the bridge are summarized in the thesis. On the background of Ramp North near Shahebao New Railway Station of Chengdu, which is a continuous rigid frame curved urban overpass with small radius, steel box and steel pier, a spatial finite element model of the whole bridge is built up with beam element using the large scale finite element software called MIDAS/CIVIL2010. Based on the model, the static behaviors are analyzed under actions including dead load, live load, centrifugal force, system temperature variation, temperature gradient, wind force, braking force and their necessary combinations; the elastic stabilitiy of the bridge at construction stage and operation stage is analyzed, and the stability coefficients and the corresponding modes of the bridge are obtained; free vibration modes and frequencies of the bridge are computed in the term of subspace iteration method; the seismic responses of the bridge are analyzed using response spectrum method and time history method, the earthquake resistant performance is known. Afterward, a detailed spatial finite element model of the whole bridge is established based on plate and shell elements using the large scale finite element software called ALGOR. Based on the model, the deformation and the detailed stress under the action of combinations of dead load, unfavorable vehicle loads, system temperature variation are analyzed. Finally, what the double bearings and single bearing with different eccentricity at a intermediate pier has the influences on torsional deformation of girder, bearing reactions and natural vibration features of structure under the action of dead load are analyzed and compared, then the worst torsional deformation of girder at the intermediate pier under the action of combination of dead load and vehicle loads is analyzed and compared. Therefore, the static and dynamic performances of continuous rigid frame curved overpass with small radius are comprehensively understood, and analysing method of complex bridge is mastered by the author.