The historic Loch Arklet dam in Stirlingshire, Scotland provides water to the City of Glasgow. Originally completed in 1914 by Charles Brand & Son, the dam required work to maintain its continued use.

Our role was to design, install and test 64 vertical ground anchors through the concrete core of the existing dam, into the underlying bedrock. Weighing up to 2 tonnes each, these are some of the highest capacity ground anchors in the UK.

Project Highlights:

• We fitted the anchor heads with ‘top-hats’, allowing the client to re-stress the anchor in the future, without disruptive works.
• With limited access to the site, we used a reverse circulation flush method, disposing of waste as efficiently as possible.
• Our geotechnical team used iPads on site to create a fully compliant handover document for the client.
• We delivered some of the highest capacity anchors in the UK, with future-proofing built in.

Anchors built for the future

Following best practice guidance, we fitted all the anchor heads with sealed, corrosion protected ‘top-hats’. This innovative technique allows the client to re-stress the whole anchor, or an individual strand, if they ever detect any drop off in load. This is a huge benefit for the client as it means they can maintain the anchors for longer, without undertaking more disruptive works.

Reverse circulation

The site’s access constraints created a particular challenge for our team. There was only one, very restricted route from the southern end of the dam, which made drilling, anchor installation and stressing challenging. To make better use of the space, we implemented a reverse circulation method to dispose of all the waste through a complex system of dewatering, skips and tankers. This took water away from drilling activities, and created more space for critical tasks.

Digital compliance

Digitally-led where possible, our geotechnical team used iPads on site to carefully record our activities. We then sent all the photos and information to our digital model, creating a complete, validated handover document for the customer, in unbiased digital form.

The result

This project is a prime example of how we use collaboration to maximum effect. We worked as one team with the client and main contractor, overcoming every logistical and technical challenge we faced, to deliver an important set of high capacity anchors – with future-proofing built in.