Oblique bending in U-shaped steel sheet piles

U-shaped Larssen steel sheet piles are normally driven in pairs. The common interlock may be crimped or welded to prevent inter-pile movement, creating an asymmetric section which may exhibit a reduced bending strength due to oblique (biaxial) bending. The recently introduced Eurocode 3: part 5 takes this into account and applies a reduction factor on bending strength. This paper provides information on the selection of values for the reduction factor and will be of interest to designers of U-section steel sheet pile retaining walls. Experimental tests carried out on one-sixth scale U-piles are reported, together with a theoretical analysis of oblique bending. The research shows that freedom of lateral movement is important to the development of oblique bending. Furthermore, pile walls restrained against lateral movement by soil–structure interaction, among other things, will not exhibit significant oblique bending