Low-Cycle Fatigue Strength of Steel Piles under Bending

Clamped abutment piles for integral abutment bridges experience both a compressive normal force and bending load cycles stemming from daily and yearly temperature variations. This paper describes experiments using full-scale models of clamped piles to demonstrate that a steel pipe pile can accommodate large inelastic deformations under strains six times greater than the yield strain for several hundred load cycles. This indicates that by permitting pile strains in excess of the yield strain (which is not permissible under most current design codes), integral abutment bridges could be erected with spans of up to 500 m and a projected service life of 120 years. The tests were carried out as a step towards the development of deign rules for determining the capacity of piles for integral abutment bridges.