Reliable Earth-Retention & Groundwater Control Solutions
High-Strength Secant Pile Walls for Challenging Excavations.
As a nationwide design-build contractor, Schnabel constructs structurally sound secant pile walls that provide both excavation support and groundwater control for challenging projects.
Using advanced specialty drills and decades of expertise, Schnabel delivers secant pile walls that help clients achieve stability and impermeability—even in the most demanding conditions.
How Secant Piles Work
Secant piles are part of a rigid, robust system that combines earth retention and groundwater cut-off walls. Secant pile walls are constructed by drilling in a series of alternating primary (drilled first) and secondary (drilled second) overlapping shafts to form a continuous secant wall. The concrete in the shafts can be all low-strength, all high-strength, or a combination of low-strength primary and high-strength secondary shafts. Steel piles or reinforcing steel are typically placed in the secondary shafts. Unreinforced high-strength shafts can also be constructed in a self-supporting circular ring, such as those frequently used for access shafts to tunnels.
Secant pile walls are relatively impermeable and can be used to control the flow of groundwater into an excavation and limit draw down outside the excavation. Secant walls are also very stiff and are often used when there are sensitive structures behind the wall.
Advantages of Secant Pile Walls
An advantage of using secant piles for cutoff wall construction is the ability of Schnabel’s high torque drill rigs to penetrate hard-drilling conditions while simultaneously casing the drill hole. These drills can advance a cased hole through man-made and natural obstructions including cobbles, boulders, and reinforced concrete.
When difficult drilling conditions are anticipated, secant piles can be a very economical method for cutoff wall construction. Another benefit is the relatively low cost of mobilization when compared to other cutoff wall types such as slurry walls and soil mix walls.
Secant Pile Wall Solutions
Schnabel designs and builds secant pile walls to meet unique project requirements and environmental challenges. These walls are constructed from overlapping concrete shafts that create a continuous, rigid barrier ideal for excavation support and groundwater cutoff.
We offer the following solutions:
Excavation support in urban or sensitive areas
Groundwater barriers and cutoff walls
Tunnel access shafts
Deep excavations in difficult soils or rock
Why Schnabel?
With decades of experience providing earth- and water-retention solutions, Schnabel is trusted nationwide for secant pile wall design and installation. Our precision drilling capabilities, combined with innovative engineering, ensure your wall performs exactly as required.
Here’s why clients choose Schnabel:
Partner with Schnabel for a Secant Pile Wall That Delivers Strength and Stability.
Real-World Results in Secant Pile Construction
Projects Schnabel Has Worked On
Here are some projects where Schnabel’s secant pile solutions played a key role:
Rondout West Branch Bypass Tunnel Shaft
Location:
Wappinger Falls, NY
Client:
Schiavone Construction Co, LLC
Background
The project involved constructing a new bypass tunnel beneath the Hudson River to ensure continued water delivery to New York City after leaks were detected in an older tunnel.
Schnabel’s Solution
Schnabel installed secant piles in a self-supporting circular ring, reaching depths of about 87 feet. The piles were drilled through fill, dense sands, and gravel, and were anchored into a shale bedrock layer located 15 to 20 feet below the surface.
Results
The secant pile shaft provided a stable and watertight excavation, enabling safe construction of the bypass tunnel.
Ohio River Tunnel
Project
Location:
Louisville, KY
Client:
J.F. Shea Construction, Inc./Traylor Brothers
Background
The Ohio River Tunnel project required the construction of a launch shaft, pump station, and retrieval shaft to support tunneling operations beneath the city.
Schnabel’s Solution
Schnabel designed and installed a series of overlapping, unreinforced secant piles in a circular ring pattern. The secant piles reached depths of up to 113 feet, penetrating the underlying dolomitic limestone bedrock.
Results
The secant pile system provided the stability and groundwater control needed to safely construct the shafts for the tunnel project.
Ready for a Secant Pile Wall Built to Perform in the Toughest Conditions? Let’s Talk.
Partner with Schnabel to design and construct a secant pile wall that meets your excavation and groundwater control needs with unmatched precision and strength.