Design, management and construction of a mixed structure bridge

Abstract

In this document, it is presented a mixed structure bridge, which was developed privately, with the property owner, who wanted to join his two plots of land divided by river, the distance is 12 meters. The bridge had to support a light load vehicle at maximum capacity (1.5 ton. in total), according to the owner’s need. Due to the time and monetary investment available, we opted for a reinforced concrete bridge slab structure on ASTM A36 steel beams assembled in I-Shape section. The design of symmetrical steel beams was found to be limited by flexure, shear, local buckling and deflection. For the flexure effect, the inertia of the beam and its torsional stability were considered, in order to comply with compact requirements in web and flange. In the construction process, was important the coordination among the stirrup´s fabrication, the prefabricated metal beams, the cut of steel plates to advantage material, the joining process, the welding process and the assembled beams assembly on site. The images show a type of shear connector between beam and slab concrete, but this is not part of the design, this consideration was taken for a future possibility that the client may wish to use the bridge with a heavier vehicle and the structure would have greater resistance.