ABSTRACT
The paper presents the results of the numerical study and field testing of shell steel structure under backfilling. For these purposes a soil-steel bridge with span of 17.67 m and height of 6.05 m was chosen. The steel shell is made of corrugated steel plate of thickness 0.007 m and has a corrugation depth of 0.14 m and pitch 0.38 m. The assembled shell structure was backfilled with soil layers of thickness ranging from 0.2-0.3 m, which were then properly compacted (min. ID = 0.97). Numerical analysis was conducted using the DIANA program based on finite element method. The assumptions of computational 3D model of shell structure with linear interface layer are also described. The corrugated steel plate elements are defined by shell-type elements as an elastic-plastic material and the backfill will be modelled using the non-linear elastic hyperbolic Duncan-Chang model. The highest axial force and stresses in the shell structure observed on additional ribs near the supports and at 1/4 height of shell. Maximum axial forces and stresses were compressive. The greatest bending moments are also compressive and they occurred at the additional ribs (at the 1/4 of height) and at shell crown. The maximum displacements situated near the shell crown and at the end of structure. The displacements obtained from the measurements and finite element analysis are generally quite close to each other. The maximum strains were observed near the support of shell and at 1/3 of shell height. The calculated values are smaller than those obtained from the field test (maximum differences were ca. 20%).
