Correspondence. The Bearing Capacity of Screw Piles and Screwcrete Cylinders.

Discussion of “Improved cone penetration test predictions of the state parameter of loose mine tailings”

“…Soil flows around the CPT during a sounding, akin to a fluid where the situation is better described by velocities rather than strains, but such analyses for sands seem beyond current mechanics. Hence, the widespread adoption, following Gibson (1950), of cavity expansion is an analogue for CPT (or pile) penetration. The beauty of the analogue is that stress and strain rates are both coaxial and in fixed direction, while symmetry reduces a 3D problem to a single spatial variable (radius to the moving element) --complex soil behaviour becomes readily computable.…”