A program of field loading tests was conducted to measure the axial response of drilled foundations constructed using a variety of different drilling techniques. The research was performed at the Auburn University National Geotechnical Experimentation Site at Spring Villa, Ala. in Piedmont geology composed of silty soils formed by weathering of parent metamorphic rocks. A total of ten drilled shafts ~0.9 m diameter by 11 m deep! were constructed using techniques including dry construction with casing advanced ahead of the hole and with drilling slurry composed of polymer fluids and mineral bentonite fluids.