文摘
The behaviour of reinforced concrete double-trough bridges has been assessed regarding the stress distribution in the transverse direction of the slab. Two bridges were studied and the curvature, as well as the tensile steel reinforcement strain, was monitored. One bridge was loaded with a reference train, producing a distributed load of 17.1?kN/m on a theoretical 1-m-wide slab strip, while the load on the other bridge was not specified. Each bridge consisted of two parallel troughs, presumably cast on different occasions, and connected by continuous reinforcement and a concrete shear stud. Previous assessment calculations regarded these two troughs acting as two separate structures, with the slab simply supported by the main beams. This paper, however, shows that there is a composite action between the troughs, and the bridge deck should instead be regarded as continuous in the transverse direction. By using this approach, the load capacity of the bridge can be increased without strengthening. Structural health monitoring using curvature- or tensile strain monitoring, is finally recommended for double-trough bridges and an assessment chart is proposed for the Haparanda Bridge.