In order to have proper composite behaviour, bond strength should be achieved at the interface either by natural bond (friction) or by means of mechanical shear connectors. it can be provided for a building column or for a closed-end driven pile. on the other hand, after driving an open-ended...
i have reviewed a few past threads on this, however, those were not directly related to "natural bond strength". there was a similar case reported on "pre-drilled" pile shaft.
"Tests by Bridge on rectangular CFTs bent both uniaxially and biaxially showed that the concrete core only provides...
combined axial+flexural behaviour is of concern, indeed. you may take it as "beam-column". because piles are supporting a pier deck and also subject to berthing/mooring loads of vessels.
i am currently working on the design of "concrete-filled steel circular marine piles". as i see most of the CFT research is on building columns but there is no design recommendation or implementation on marine piles.
in case of closed-ended pile driving, one can ensure that required bond...
