The strength design of deeply buried circular corrugated steel arches with considering only soil radial restraining

Buried circular corrugated steel arches (BCCSAs) are often adopted in underground engineering. However, the current design specifications cannot accurately estimate the BCCSA's load-bearing capacity due to the complicated interaction between the soil and the arch. This paper presents the strength design recommenda-tions for deeply buried circular corrugated steel arches with various rise-span ratios under axial compression and under combined axial compression and bending moment respectively, with meeting a proposed width- thickness ratio limit of the BCCSA for local buckling prevention. At first, a finite element model (FEM) of sinusoidally corrugated steel plate (S-CSP) for analyzing its local plate buckling under axial compression (FEM-l) is established, and this FEM can eliminate other possible buckling modes except the local buckling mode by constraining the out-of-plane displacement at the crest and valley lines in S-CSPs. Through FEM-l, the local buckling behaviors of S-CSPs are studied and the width-thickness ratio limit of S-CSPs under axial compression for local buckling prevention is determined in terms of a design principle that local buckling of plate elements does not occur before fully sectional yielding. Then, a global arch-spring model of BCCSA is established for analyzing its elastic global buckling, with considering the interaction between the soil and arches by simplifying the radial restraint of soil as radial unidirectional springs around the arch. The normalized slenderness of BCCSA in the arch-spring model is obtained from its elastic global buckling load calculated by theoretical derivation with bidirectional spring assumption. Finally, the ultimate load-bearing capacity of BCCSAs is calculated by employing elastoplastic finite element models under axial compression and under combined axial compression and bending moment respectively. Based on extensive numerical results obtained in this study, the conservative strength design methods for BCCSAs are proposed in practical engineering applications.