Perimeter Load Transfer in Model Drilled Shafts Formed under Slurry

Abstract

Experimental laboratory‐scale studies were conducted on the effect of the use of various mineral and polymer drilling slurries on the perimeter load transfer in drilled shafts in saturated sand. Parallel measurements were also made of the rheological properties of the slurries studied in order to develop ranges of slurry control properties consistent with predictable load transfer. Polymer slurries, mixed in medium to high doses, were found to be as effective as the more familiar mineral slurries in the development of load transfer. No slurry, however, produced the magnitude of perimeter load transfer that was developed on model drilled shafts constructed by inserting casing ahead of the drill in medium‐dense, saturated sand and withdrawing the casing as the simulated concrete was placed.