Secant Pile Wall Design

Operating throughout the country, Schnabel is a reputable design-build corporation recognized for its construction of dependable and structurally solid secant pile walls. These walls provide a dual function, supplying both strong excavation support and effective groundwater barriers.

The design of secant pile walls consists of exceedingly rigid shafts that overlap each other, creating a continuous concrete barrier. The process of drilling these secant pile shafts involves advanced drills designed to ensure precise alignment, which is essential for their functionality. These shafts generally range from 2 to 4 feet in diameter. Similar in construction, tangent piles differ from secant piles in that their shafts merely touch but do not overlap.

Schnabel’s experience spans over decades, specializing in custom-made solutions for earth and water retention. Given this expertise, Schnabel can construct secant walls that effectively assist you in overcoming even the most challenging construction objectives.

Secant Pile Wall Design Solutions

As part of a rigid, secure system, secant piles merge the functions of earth retention and groundwater containment walls. The construction of secant pile walls involves drilling and alternating primary (drilled first) and secondary (drilled second) shafts that overlap one another, forming an unbroken secant wall. The concrete used in the shafts could either be purely low-strength, entirely high-strength, or an amalgamation of primary low-strength and secondary high-strength shafts. Secondary shafts frequently feature steel piles or reinforcing steel. Non-reinforced high-strength shafts can also be erected in a circular layout for self-supporting purposes, a common choice for access shafts to tunnels.

Characteristically near waterproof, secant pile walls aid in controlling groundwater seepage into excavation sites and restrict external drainage. Owing to their stiffness, secant walls are a popular choice when surrounding sensitive structures.

A noticeable advantage of employing secant piles for cutoff wall construction lies in Schnabel’s high torque drilling rigs’ capability to maneuver through challenging drilling conditions whilst concurrently casing the drill hole. These drills can still proceed with casing a hole even through human-made and natural obstructions such as cobbles, boulders, and reinforced concrete.

In anticipation of challenging drilling scenarios, secant piles offer a cost-efficient solution for constructing cutoff walls. Additionally, they are less expensive to mobilize compared to other forms of cutoff walls like slurry or soil mix walls. If you’re deliberating if a secant wall is the most suitable solution for your project, reach out to any of Schnabel’s eight regional offices today for more insight.

Always innovating new approaches to better solve old problems.

secant pile contractors

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.

secant piles

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.
Paul Davis, Rondout West Branch Bypass Tunnel Shaft


Schnabel is the sector’s most operationally efficient Geostructural Design & Construction contractor. We optimize efficiencies by leveraging decades of experience and design/build expertise to innovate processes and approaches that are consistently proven to deliver optimal outcomes for our clients.