Secant Pile Wall Construction Method
Schnabel, a countrywide design-build organization, is proficient in executing the secant pile wall construction method to build dependable and structurally solid secant pile walls. These walls effectively function as both excavation supports and groundwater barriers.
The construction method for secant pile walls involves the use of exceptionally stiff, overlapping shafts to create a continuous concrete wall. Specialized drills are utilized for drilling the secant pile shafts, ensuring the critical alignment necessary for the effectiveness of the secant pile wall. These shafts typically range from 2 to 4 feet in diameter. Though similar to secant piles, tangent piles only have shafts that touch without overlapping.
With their wealth of experience over several decades in delivering customized earth- and water-retention solutions, Schnabel has the know-how to construct secant walls that aid in achieving your toughest construction objectives.
Secant Pile Wall Construction Method Solutions
Secant piles form a steadfast, robust system that merges the dual functions of earth retention and groundwater cut-off walls. Using the secant pile wall construction method, walls are constructed by drilling a series of alternating primary and secondary overlapping shafts to produce a continuous secant wall. The concrete filled into these shafts could be totally low-strength, solely high-strength, or a mix of low-strength primary and high-strength secondary types. Typically, the secondary shafts embed steel piles or reinforcing steel. Additionally, unreinforced high-strength shafts can also be constructed as self-supporting circular rings, a structure often employed for tunnel access shafts.
Relatively impermeable, secant pile walls are used to control the inflow of groundwater into an excavation and limit external draw down. Due to their considerable rigidity, secant walls are commonly utilized when sensitive structures are located behind the wall.
One of the main advantages of applying the secant pile wall construction method for building cutoff walls lies in Schnabel’s capacity of their high torque drill rigs. These can pierce through tough drilling conditions while simultaneously casing the drill hole. These drills are also capable of driving a cased hole through both man-made and naturally occurring obstructions like cobbles, boulders, and reinforced concrete.
In situations where challenging drilling conditions are expected, the secant pile wall construction method presents an economical approach for fabricating cutoff walls. Another advantage is their relatively lesser cost of mobilization in comparison to other types of cutoff walls like slurry walls or soil mix walls. If you’re contemplating whether a secant wall is the suitable solution for your venture, please feel free to contact one of Schnabel’s eight regional offices today.
Always innovating new approaches to better solve old problems.
Rondout West Branch Bypass Tunnel Shaft
Schnabel installed secant piles in a self-supporting circular ring to support the construction of a new bypass tunnel to allow water to flow under the Hudson River to New York City after an older tunnel started to leak.
Barnes-Jewish Hospital
Schnabel designed and constructed a secant pile wall for the Barnes-Jewish Hospital Parkview Tower on the Washington University Medical Campus in St. Louis, Missouri. The perimeter secant wall served as both the permanent structural basement wall and the temporary earth-retention system for the new hospital building.
In 31 years of building deep foundation projects for Schnabel, building a 90’ deep reinforced circular shaft was one that was very challenging and deeply rewarding. Looking forward to working on the next one with our client Schiavone.
