Structural capacity of the steel pipe without any infill (hollow) is adequate. Concrete infill is only required to increase stiffness for deflection. The top of plug is well below the depth of fixity, so the stresses in pipe and deflection is not an issue at this buried location. Pile was...
A soil plug has developed in a 3 foot diameter pipe while driving into 6 inch minus rock fill. Top of plug is approximately 20 feet from grade; so it could potentially be possible to fill with reinforcement and concrete infill and be well below the the depth of fixity. As long as the PDA results...
