Full scale tests of various buried flexible structures under failure load

The aim of the tests described in the paper was conducting a displacement and stress analysis of four buried flexible structures made in different technologies under failure load. Generally, the laboratory tests carried out on in full scale confirms that all four culvert models of the work safely despite the reduction of the backfill layer over the structures to 0.3 m (less than according to standard recommendations) and increasing the load to 1960 -2000 kN (almost 4 times more than according to standards and recommendations). In the case of a PE plastic pipe, the main measured parameter was displacement and for other steel research models it was the stress. The obtained maximum values of these parameters were compared with the permissible standard values. Maximum displacement values were recorded in the crowns of the structures up to 12.57 mm for PE plastic pipe model. The maximum stresses for steel structures were 85.28 MPa (for corrugated steel pipe), 111.5 MPa (Box Culvert) and 447.9 MPa (Multi Plate non-circular structure). Despite the exceed stress in the case of Multi Plate structure, the steel structure did not lose its stability. The analyses carried out were aimed at determining database, which in its assumption, allows the verification of calculations performed by a numerical method such as FEM.