CFA Mega Piles: Foundation in Elk Hills Field
The Elk Hills Field in Kern County is one of the United States’ largest natural gas and oil producing fields. This project called for a new Cryogenic Gas Plant and Fractionation Facility to be built on a former pipe storage yard, near existing gas and oil processing facilities. The foundation work was designed to support a variety of structures including pipe racks, vertical vessels, compressor shelters, air coolers, fuel storage tanks, and operation control facilities scattered across the 400 x 1,500 foot rectangular site. CFA piles, 18 and 24 inches in diameter, were chosen for the site due to the sandy subsurface conditions.
A Bauer RTG 23S equipped with a 65-foot auger was used to install all piles. Drill depths ranged from 20 to 60 feet with an average of 35 feet. Every pile received a rebar cage up to 25 feet, and in certain areas, a full-length center bar was added to increase tension capacity of the pile. The project was divided into two phases. The first phase with 430 piles had wide-open access with no obstructions and high production rates. For Phase 2 (617 piles), many separate concrete footings had to be constructed, restricting access for many of the piles, and pile production decreased accordingly.
