Buried corrugated structures are subjected to highest stresses during two phases: during backfilling and under service loads. Commonly, deformations during backfilling are more unfavorable for the structure than those that occur under service loads. Typically, service loads will generate several times less deflection than do construction loads falling below the limit of deflection ( w) to span ( L) of w/L = 2%. For the sake of modeling the behavior of corrugated steel structures during backfilling, separate components (i.e., corrugated steel, backfill, road structure) of the soil structure are represented by independent parameters such as deformation module, Poisson's coefficient, and soil unit weight. A steel plate is described in geometric terms. Modeling the deformation of buried corrugated structures with finite element modeling is very difficult because of the complex characteristics of the soil medium during construction of the backfill. An analytical algorithm was used to calculate characteristic deformations of a steel structure during backfilling. The algorithm was analyzed with respect to chosen physical and geometric parameters. Deformations during backfilling of a corrugated structure are described, and correlations of specific points of a structure are presented in a mathematical form on the basis of in situ tests in natural scale. The algorithm was prepared assuming the average backfill quality required by good construction and design practices. The results of this research are applicable to structures with closed and open shapes, except for boxes.

No abstract

In soil-steel bridges usually the massive concrete foundation is being applied. When the structure is mounted in the gutter, the static models defined as non-sliding joint arch. In a few cases only, the corrugated steel structures are founded on a flexible foundation. The examples of such objects executed in Poland were described in this article. The flexible foundation of the steel structure helps to form a natural vault in the backfill. The shape of the structure, similar to parabolic arch, is relevant in this case. The essential case being analyzed here, is the structure founded on the piles made of steel pipes. It is characterized by variable static scheme resulting from the level of connection. The displacement scheme was established using the results of geodetic measurements performed on the constructed bridge. On this basis, the range of changes in the uplift of the structure during backfilling, was estimated in the structure model. Keywords: Soil-steel bridges; Flexible foundation; Static scheme; Investigation