“What are secant walls?”

Secant walls are continuous underground walls. Typically, a secant wall is made by overlapping drilled concrete pilings and is used for retainment and shoring purposes. Our secant wall project along the shore of Lake Ashburton was a secant wall, for example.

The piles that make up a secant wall are either labeled as primary or secondary piles. We start by drilling primary, alternating piles and filling them with concrete. After the primary piles have achieved a specified strength, we drill secondary piles between the primary piles. We space secondary piles to overlap the primary piles by between 3 and 6 inches. Afterward, we reinforce the secondary piles with a rebar cage or a steel beam and fill them with concrete. Compared to sheet piling methods, a secant wall is much stronger. It also generates less vibration and less noise during construction, so it’s ideal near buildings and structures.

If you need a noise wall constructed for your project, contact us for an estimate.

Secant wall diagram
Secant wall construction