LAUSR

Abstract Local buckling may occur in the straight portion of a corrugated steel plate (CSP) pipe-arch with a deep wave section that is used in a buried structure. In this study, the soil support of the pipe-arch structure is considered, and the local buckling of the straight portion of the CSP is investigated. The corresponding theoretical formulae are derived using the Rayleigh-Ritz method. The simplified mechanical model with the soil support is used for derivation. Then, the finite element models for the invert of the pipe-arch with several waves are established to analyze the actual rotational restraints of the straight portion. The influences of plate thickness, corrugation, aspect ratio and curvature on the local buckling load of the invert are investigated. The relationships of plate thickness and local buckling load for three types of deep corrugations are obtained. These relationships reveal that the actual rotational restraints are negative, i.e., the straight portion provides restraint for the corrugated portion. Based on numerical simulations, the theoretical formulae are modified to account for the actual rotational restraints of the straight portion. Then, the finite element model of the global pipe-arch structure is built. The corresponding analysis matches well with the revised formula, which validates the modified derivation. Finally, according to the yield criterion, a reasonable limit value for the width-to-thickness ratio for the straight portion of the CSP is suggested. This limit can be used to prevent local buckling of CSP buried pipe-arch structures in practice.