Secant Piles
Secant pile walls are an innovative way to build subterranean structure walls and retaining walls. They are formed by a series of interlocking and contiguous drilled shafts, which are constructed using primary piles and secondary piles that are made of soft concrete and become interlocked when set. They are used primarily where there is a high water table or unsuitable ground conditions. Secant pile walls are attractive near buildings, roads, and other sensitive structures due to lack of noise and vibration during construction. Secant walls can be used to form a continuous water-resistant wall – an added benefit on environmental projects. The final product provides a fully concreted face and can be an effective alternative.
Secant Pile Wall
RECON used its state-of-the art Delmag RH 190 top head drive drilling rig to build a 140 by 240 by 25 feet deep, 6-million gallon stormwater run-off holding tank. To create this watertight structure, RECON installed 306 secant piles to a depth of 60 feet.

Project Features
• Drilling secant pile shafts that interlock to form a continuous wall
• Installing the 3-foot diameter secant piles on typical 2-foot, 6-inch centers, which produced a 6-inch overlap to form a 30-inch wide pile for the structural exterior wall of the holding tank.









