Drilled shafts are large diameter piles drilled with a high torque machine for very high capacity foundations. Drilled shafts can be cased as required depending on soil conditions.
Reinforcing steel is placed in the excavated shaft and then concrete is placed by a full depth tremie pipe to fill the shaft. Drilled Shafts are very high capacity and are drilled with various tools including dirt augers, rock augers, core barrels, rock buckets, and clean out buckets.