Failure mechanisms of weld-beaded grouted pile/sleeve connections

This paper describes in detail the observations from a series of push-out tests on grouted pile/sleeve connections with weld-beads. As opposed to previous tests aimed at quantifying overall connection strength, the current series was aimed at identifying the load-transfer and failure mechanisms involved. Another aim was to obtain local stress-slip relationships for use in nonlinear modelling of the connections. The results indicate that certain failure modes used to derive strength expressions in some codes are post-failure phenomena and are not the primary failure mechanism. It is also observed that failure of the connection is associated with hoop yielding of the pile, leading to a sudden drop in confining stress. The experimental results indicate that an increase in weld-bead height does not lead to an increase in capacity commensurate with code predictions.