Secant or tangent piles are columns constructed adjacent (tangent) or overlapping (secant) to form structural or cutoff walls. From soil mixing to drilled shafts, Keller draws on its complete suite of techniques to optimize the design and construction of these walls.

Secant or tangent piles technique image

Common uses

Provide slope stabilization
Enable and support excavations
Support bulkheads
Create barriers to groundwater flow

Process

The columns are constructed using soil mixing, jet grouting, auger cast, or drilled shaft methods. Sequenced construction of the elements helps ensure a tight seal for water cut off. The design can incorporate steel bar or beams for reinforcement. Anchors provide additional lateral support, if needed. Secant or tangent pile walls can be constructed in a wide variety of soil conditions, including through cobbles and boulders.

Secant pile walls retained by anchors or strutting system are often supported by a waler beam to distribute the loads (prevent punching of anchor/strut through the pile) and as a mitigation measure for the unlikely event of an anchor/strut not carrying the load. This waler beam can be constructed as a reinforced concrete beam casted towards the pile wall, or by using steel profiles to be fixed to the piles and anchors/strutting systems.

Advantages

Can be constructed in a wide variety of soil conditions, including through cobbles and boulders
Very little deformation and settlement on the outside
Can carry high loads from surrounding structures
Less vibration during construction

Quality assurance

We use the latest technology, testing regimes and best practices protocols developed over many years to ensure the position, verticality and structural integrity of our pile walls.