Design and Construction of Steel and Concrete Continuous Composite Rigid Frame of Changping Overpass Bridge

The Changping Overpass Bridge is a steel and concrete continuous composite rigid-frame bridge arranged in two continuous units,each being(37+60+79+42.5) m and(42.5+79+42.5) m.The main girder of the bridge is designed as a steel and concrete composite one,of which the steel box girder is of the single-cell,single-box and vertical web section and the deck slabs are the reinforced concrete structure.The box girder is rigidly fixed with the concrete pier shaft at the intermediate pier and all pier columns of the bridge are the rectangular ones.The finite element program MIDAS Civil was used to establish the calculation model for spatial structure of the whole bridge,the static force of the bridge was calculated and analyzed and the results of the calculation and analysis proved that the stress and structural strength of the box girder could meet the relevant requirements in the codes.To minimize the interference of construction to the traffic under the bridge,the box girder was fabricated in shop and lifted in place at the bridge site.The precast deck slabs were installed by the discontinuous method in the sequence of the parts of the bridge at the midspan first and the parts close to the supports late.