Applications > PILE Retention

PILE RETENTION

Using earth anchors for pile retention involves securing the pile face by anchoring them horizontally into stable soil layers. The earth anchors provide lateral support, counteracting soil pressure behind the pile face when full excavation depth is achieved, this minimises pile deflection.

Earth anchors offer a range of advantages for pile retention compared to traditional methods like shoring and grouted anchoring. Earth anchors are highly flexible in terms of positioning, allowing engineers to adapt them to different soil conditions, load requirements, and site constraints. This flexibility enables a more precise application for supporting excavation faces and retaining walls without extensive excavation, reducing both project costs and environmental disturbance.

In contrast, shoring systems, which typically involve large support structures like sheet piles or soldier piles, require more extensive excavation and can occupy significant site space. Shoring can be less adaptable to complex or variable soil profiles and often needs a larger footprint, making it less ideal for constrained urban environments. Additionally, shoring systems can be challenging to modify once installed, limiting the ability to adjust support as conditions change.

Grouted anchoring, another common lateral support method, involves drilling into the soil and injecting grout to secure the anchors in place. While grouted anchors provide solid support, they are typically more time-intensive to install and require careful monitoring of the grout’s curing process to ensure stability. This method can also be more susceptible to environmental constraints, such as groundwater conditions, that may affect grout performance. Earth anchors, by comparison, are quicker to install and do not rely on grout curing, enabling faster project progression and offering a durable, low-maintenance alternative.

In sum, earth anchors provide efficient, adaptable, and environmentally friendly lateral support, especially in projects where space constraints, time, and environmental factors are critical considerations.

How it Works

Pile Retention Anchoring involves a three steep process. These steps involve installation and testing, anchor locking off, removal and de-stressing of anchor tendon

1. Installation and Testing – This involves the driving of anchors between the piles to the engineer specified depth and angle. The anchors are then proof tested with a NATA accredited load cell to ensure accurate readings of holding capacity. 

2. Locking Off – After the shotcrete has been completed the team will install waling beams above and below the anchor tendon. The anchor will then be locked off under the engineered specified load, spreading the holding force over the waling beams. 

3. De-stress and Removal – Once the builder has poured and tied in the slabs to the piles, the anchor tendons will be removed from the ground leaving only the sacrificial anchor head.

 

FAQs

Why are earth anchors used for pile retention?

Earth anchors provide additional stability to piles by securing them against lateral movement, soil shifts, and external forces, ensuring minimal pile deflection when excavating to full depth.

What types of piles can be stabilised with earth anchors?

Earth anchors can be used for various pile types, including  CFA piling, sheet piling and, in applications such as retaining walls, foundation support, and deep excavations.

How are earth anchors installed for pile retention?

The anchors are percussion driven into the ground at engineered locations, depth and angles. Then proof tested with specialised equipment. The anchors are then lock off to the pile face using steel beams and a locking nut which is screwed to the anchor tendon

Can earth anchors be used in all soil conditions for pile retention?

Yes, earth anchors are designed to work in a wide range of soil types, including clay, sand, and rocky terrain, by reaching stable layers to ensure secure retention. The loads achieved are dependent on soil conditions however, the vast range of anchor types allows us to achieve results in all conditions.

What are the benefits of using earth anchors for pile retention?

Earth anchors offer a cost-effective, non-invasive, and durable solution, reducing the need for extensive excavation while providing strong lateral support. Providing instant load after installation decreases waiting to for further excavation.

Do pile retention anchors require ongoing maintenance?

Minimal maintenance is needed, but periodic inspections are recommended to ensure anchor tension and structural stability remain intact, especially in areas with soil movement. Depending on the engineered requirements these checks may not be required.