Experimental study of critical and post-buckling behaviour of prestressed stayed columns

A full scale experimental investigation into the strength and behaviour of prestressed steel stayed columns in compression has been conducted. Results, including full load versus end-shortening curves, for a total of 18 test specimens are presented. Two critical modes of buckling — symmetric and antisymmetric — with interactive post-buckling are demonstrated experimentally and the imperfection sensitivity of the stayed columns is investigated. Interactive buckling is observed primarily when the individual buckling loads of the antisymmetric and symmetric modes are close or when the antisymmetric mode is critical. Analysis of the results reveals that increased prestress leads to an increased load-carrying capacity when instability occurs in the symmetric mode, but the reverse trend is found when the antisymmetric mode is critical.

► Full-scale experimental investigation of prestressed steel stayed columns.
► Physical demonstration of antisymmetric and interactive buckling for the first time.
► Antisymmetric mode tends to trigger interactive post-buckling.
► Increasing prestress found to increase capacity in symmetric mode.
► Increasing prestress found to decrease capacity in antisymmetric mode.