Secant walls constitute a sturdy, resilient system that blends earth retention and groundwater barrier walls. The secant pile wall construction process involves drilling an alternating series of primary and secondary overlapping shafts to establish a continuous wall. The concrete in the shafts could be entirely low-strength, wholly high-strength, or a blend of primary low-strength and secondary high-strength. Typically, steel piles or reinforcing steel are situated in secondary shafts. Unreinforced high-strength shafts can also be formed into a self-supporting circular ring, commonly utilized for access to tunnels.
Due to their relative impermeability, secant pile walls can be leveraged to manage the seepage of groundwater into an excavation and curb the draining outside the excavation. The significant stiffness of secant walls makes them an ideal choice when sensitive structures are present behind the wall.
One of the benefits of employing secant piles for cutoff wall construction lies in Schnabel’s high torque drill rigs’ ability to navigate through hard-drilling conditions while simultaneously casing the drill hole. These drills can manage to make a cased hole advance even in the presence of both man-made and natural impediments including cobbles, boulders, and reinforced concrete.