PERIMETER LOAD-TRANSFER IN MODEL DRILLED SHAFTS FORMED UNDER SLURRY

Experimental laboratory-scale studies were conducted on the effect of the use of various mineral and polymer drilling slurries on the perime ter lend transfer in drilled shafts in saturated sand. Parallel measur ements were also made of the theological properties of the slurries st udied in order to develop ranges of slurry control properties consiste nt with predictable load transfer. Polymer slurries, mixed in medium t o high doses, were found to be as effective as the more familiar miner al slurries in the development of load transfer. No slurry, however, p roduced the magnitude of perimeter lend transfer that was developed on model drilled shafts constructed by inserting casing ahead of the dri ll in medium-dense, saturated sand and withdrawing the casing as the s imulated concrete was placed.