Secant piles form a part of a solid, resilient system that amalgamates earth retention and groundwater barrier walls. The construction of such walls by secant pilling contractors involves the drilling of alternating primary (drilled first) and secondary (drilled second) overlapping shafts to create a solid secant wall. The concrete employed in these shafts can be either entirely low-strength, high-strength, or a mixture of low-strength primary and high-strength secondary shafts. The secondary shafts often incorporate steel piles or reinforcing steel. Moreover, unreinforced high-strength shafts can also be created in a self-supporting circular ring, a common selection for tunnel access shafts.
Secant pile walls, being relatively impermeable, serve to control the ingress of groundwater into an excavation and lessen the draw down outside of it. Their exceptional rigidity makes them a preferred choice when delicate structures are situated behind the wall.
One of the upsides of utilizing secant piles for constructing cutoff walls is Schnabel’s high-torque drill rigs’ ability to navigate through challenging drilling conditions while also casing the drill hole. These drill rigs possess the ability to push a cased hole through both natural and man-made deterrents, such as cobbles, boulders, and reinforced concrete. This makes the secant pile method a highly versatile and effective solution for complex construction scenarios.