Practical Considerations in the Selection and use of Continuous Flight Auger and Drilled Displacement Piles

The use of continuous flight auger (CFA) and drilled displacement (DD) piles in the U.S. market has increased significantly in recent years. This paper describes some of the advantages and limitations of these drilling systems compared to other deep foundation systems. Geotechnical and project considerations are described which favor the use of CFA and DD piling. In addition, conditions are discussed which may be problematic for this type of construction or which may limit the practicality and competitive advantages of CFA and DD piles.