Performance of large-span arched soil-steel structures under soil loading

This paper investigates the structural behavior and soil-structure interaction mechanism of very large-span arched soil-steel structures constructed using steel plates with deep corrugation profile, 500 mm X 237 mm, during and after construction. Field measurements were employed to validate three-dimensional (3D) finite element model (FEM), which was then employed to evaluate the performance characteristics of very large span soil-steel structures. In addition, the FEM was used to evaluate the effectiveness of various strengthening techniques employed for buried steel structures to withstand very large spans, including lateral reinforced steel mesh and circumferential steel stiffeners. The world's largest-span arched soil-steel bridge constructed using 12 mm thick steel plates with the deepest corrugation profile, of 237 mm total depth and 500 mm pitch was instrumented extensively to monitor the displacements and straining actions of the steel structure. The steel structure has a span of 32.40 m and vertical height of 9.57 m. Lateral reinforced steel mesh was attached to the steel structure and cement-stabilized soil was added to a certain level to enhance the performance of the structure during and after construction. The calculated deformations and straining actions captured the same trend of the field measurements. The numerical results indicated that two main critical zones of the steel structure, the crown and at the change of arc radii (40 degrees from the top arc on each side), were observed to experience high axial stresses, which could cause buckling and should be considered carefully in the structural design. Finally, the numerical results revealed that the deployed steel mesh reinforcement in the current study reduced the induced straining actions in buried structures with up to 50%, while the investigated circumferential steel stiffeners could control the crown vertical deformations down to 0.5% of the structure rise during and after construction.