Effect of eccentricity on anchorage zone behaviour

The behaviour of prestressed concrete members in the region of anchorage zones is complex. Existing methods for determining the quantity and location of bursting reinforcement often lead to congestion of reinforcing steel in such zones. Previous investigations have suggested that conventional design methods are over-conservative, and that considerable savings can be made by using more sophisticated analysis techniques to perform the design. This paper reports the results of an experimental program that examines the effect of load eccentricity on the behaviour of strip-loaded concrete prisms with various quantities of confining steel. This program extends the work of Ibell and Burgoyne, who investigated the behaviour of similar concentrically loaded prisms. Additionally, the generalised analysis technique for concentric anchorage zones proposed by Ibell and Burgoyne is improved by the use of the semi-analytical scaled boundary finite-element method instead of the finite element method, and is extended to permit the analysis of eccentrically loaded anchorage zones.