An Evaluation of Backfill Material Applicability through Deformation Measurements of Long-Span Buried Corrugated Steel Structures

Corrugated steel plates are increasingly being applied to various types of structures, such as eco-corridors, noise reduction tunnels, and urban elevated roads. However, applications for spans exceeding 25 m are lacking, as they require clear standards for calculating the elastic moduli of backfill materials and reinforced sections. This study evaluated the appropriateness of mechanical assumptions applied in the design, by measuring displacements at each stage and comparing the finite element analysis results for a concrete-reinforced corrugated steel plate arch underground structure with a width of 27.5 m and length of 467 m. Based on the measurement results, deformations ranging from 19.8% to 63.7% of allowable deflection were observed when applying an elastic modulus of 60 MPa to solidified soil backfill, which is twice the maximum standard value applied to general soil, thereby confirming the suitability for the serviceability of underground structures.