Evaluation of Several Auger Bits in Frozen Fine-Grained Soils, Asphalt, and Concrete

Abstract : Several auger bits were evaluated for drilling in frozen ground, asphalt, and concrete to determine bit performance in a wide range of materials. Promising bits in the 9- to 10-in. (229- to 254-mm) diameter range were used with varying success depending on bit configuration. Bits included finger bits and a two-wing bit with continuous cutters. It was possible to penetrate all the test materials, with performance depending on bit parameters and characteristics of the drill rig. Drill rig specifications are important because of the high torque and vertical thrust required for drilling in these hard materials. The finger bits have an advantage over bits with fixed cutters (soldered to the bit) for this demanding drilling, since damaged and dull cutters can be rapidly replaced in the field without special equipment. Several smaller-diameter bits 3.5 in. (89 mm) to 6.5 in. (165 mm) were also tested in frozen ground only. Keywords: Auger bits, Drill bits, Drill performance, Frozen ground.