Axial-Compressive Capacities of a New Type of Tapered Steel Pipe Pile at the John F. Kennedy International Airport

Tapered driven piles have been the deep foundation of choice at the well-known John F. Kennedy International Airport (JFKIA) in New York City ever since construction of and at the airport began in the late 1940s. For many decades naturally tapered timber piles were used primarily but various brands of closed-end steel pipe piles have become preferred in recent years as design engineers have sought ever-increasing allowable axial-compressive loads per pile. Toward the end of the 20th century, construction of new passenger terminals and a light-rail system called AirTrain at JFKIA pushed existing steel-piling alternatives to their performance limit in terms of both temporary driving stresses and permanent foundation loads. This led to the development of a new type of tapered steel pipe pile called the Tapertube. This paper discusses the rapid evolution of the Tapertube pile to the degree that it is now possible to routinely install piles that have allowable axial-compressive service loads per pile in excess of 400 kips (1780 kN), with net ultimate axial-compressive geotechnical capacities per pile of the order of 1000 kips (4450 kN). This paper also discusses the results from various types of load testing performed on Tapertube piles at JFKIA both during and after pile driving, and compares these results to capacities calculated using a new (in 2002) analytical method that has shown great promise for use with tapered driven piles. Finally, this paper also draws conclusions and makes suggestions as to how other tools such as dynamic measurements that are routinely used with tapered driven piles might be improved to better reflect the current understanding of how tapered driven piles develop most of their axial-compressive capacity