Abstract

The paper concerns soil-steel bridge structures with a circular-shaped top of a shell cross-section, made of corrugated steel plates. During backfilling, the shell uplifts in the crown, and narrows in the corners. On the basis of measured displacements, the changes of radius of curvature in the crown of the shell can be specified. This is the basis for estimation of the bending moment – the main component inducing normal stress on the shell. The proposed algorithm for estimating changes in the curvature of a shell was verified by the results of in-situ measurements. Measured strains allowed for independent verification of results of calculations of curvature radius changes. Because of large displacements of steel shells, the deformation measurements can be performed with surveying techniques. This enables in-situ control of the shell deformation, during the whole period of bridge construction, including the process of backfilling. Analysis of changes in the radius of a shell curvature can be used to evaluate its safety during backfilling.