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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 recommendations 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. [Display omitted] • Local buckling prevention is implemented by proposed width–thickness ratio limit. • The soil radial restraint is equivalent to unidirectional radial springs. • Initial imperfection amplitude affects the load-bearing capacity of the arch much. • Axial compression stability coefficient under various rise–span ratios is proposed. • Load-bearing capacity is proposed for combined axial compression and bending. [ABSTRACT FROM AUTHOR]

The concrete-infilled double steel corrugated-plate walls (CDSCWs) consist of two steel corrugated plates (SCPs), infilled concrete and two boundary elements. The two SCPs are connected by high-strength bolts and the spacing between the two SCPs is filled with concrete. The two vertical boundary elements are installed at both sides of CDSCWs. The sectional load-bearing performance of CDSCWs only under uniform compression has been investigated previously by the authors. But CDSCWs under a combination of compression and in-plane bending moment are applied in practice widely and commonly. Therefore, this paper presents the corresponding sectional load-capacity design method of CDSCWs under a combination of compression and in-plane bending moment. Firstly, an experimental investigation on sectional load-capacity of an I-shaped CDSCW specimen subjected to combined compression and in-plane bending moment is completed. The experimental results reveal a high axial load-bearing efficiency of the SCPs in the CDSCW specimen, and also validated the finite element (FE) model adopted in this study. Then, the FE numerical simulation is applied to systematically analyze the load-bearing performance of CDSCWs subjected to the combination of compression and in-plane bending moment. The coefficient φ sp is introduced to consider the local buckling of compressive zone and the weakening effect of tensile-compressive transition zone in SCPs. The coefficient β c is introduced to consider the weakening effect of tensile-compressive transition zone in concrete and the adverse cooperative effect among SCPs, concrete and boundary elements owing to their different ultimate strains at the ultimate state of CDSCWs. As a result, the N - M correlation curve for predicting the sectional load-bearing capacity of CDSCWs under both the uniform compression and in-plane bending moment is then established and also verified by the experimental results. • CDSCWs have favorable sectional load-bearing capacity. • FE analyses are used to study the load-bearing mechanism of CDSCWs under in-plane combined compression-bending loads. • The weakening effects of local buckling, tensile-compressive transition zone and cooperative performance are considered. • Cross-sectional load-capacity design formulae for CDSCWs are proposed. • An experiment of an I-shaped CDSCW specimen is conducted to investigate the cross-sectional capacity. [ABSTRACT FROM AUTHOR]