Behaviour of the steel box-type culvert during backfilling

Corrugated steel culverts are increasingly used in road and railway projects as alternative solutions to small bridges and tunnels. This paper describes full-scale tests of the corrugated steel ‘box’ type culvert with a span of 3.55 m and a height of 1.62m. The corrugation pattern was 150 × 50 mm and the steel thickness was 5 mm. Two concrete strip foundations were laid under each end of the arch. The structure was tested during backfilling. Deformations and strains of the steel structure were measured while installing culvert after each layer of 25-30 cm thickness was compacted. In order to specify displacements and stresses in the steel structure, three inductive gauges and twenty two strain gauges were installed on the inside surface of the culvert. The presented tests were carried out at the Road and Bridge Research Institute, Poland, for Via-Con Company, the Norwegian culvert producer. Several full-scale tests have been done in the field to validate the long-term performance and great load bearing capacity of these structures. In contrast to that, only few tests of life-size structures have been performed under fully controlled laboratory conditions like the one in Poland. A nonlinear finite element analysis of the soil-structure system was carried out in order to simulate behaviour of the structure during backfilling. A detailed description of the finite elements used in the analysis is provided. The obtained experimental results were compared with the structure response computed using the FEM. The measured and thecomputed results are shown in tables and graphs.