Secant Wall Piles 

Secant pile walls are formed by a series of interlocking drilled shafts used primarily where there is a high water tables or unsuitable ground conditions.

Advantages of the Trench Contril Secant walls: 

• No guide wall required
• Larger distance between pile centres
• 20% less piles required
• Provides additional 1 m of space around basement perimeter

Because of the lack of noise and vibration, these walls are attractive near buildings, roads, and other sensitive structures. Secant walls can be used to form a continuous watertight wall, an added benefit on environmental projects.

Secant pile walls are constructed so the piles overlap each other. The common practice is to alternate the placement of the piles along the wall alignment, between hard & soft piles, leaving a space of a little less than the diameter of the intermediate pile. The exact spacing is based on construction tolerances where Trench Control have the largest tolerance of 500mm between centres. The intermediate piles are usually formed using a heavy temporary casing that cuts through the concrete piles on either side.

Trench Control design and construct all types of pile walls using our ABI VDW drilling rig. Typically, 600mm diameter piles are installed at 500mm centers; although this may vary depending on retained height and soil properties. The piles are installed through a computer aided sensors. There is no need for a concrete guide wall that serves as a template to maintain proper alignment and pile overlap.