Ardersier Port
Ardersier Port
Delivery of a specialist earthworks contract for a 450-acre energy transition facility.
Project Overview:
Client: Haventus
Type of Works: Groundworks & Stabilisation
Project Start Date: 2023
O’Keefe carried out extensive cement stabilisation works to create a new 1.5 km-long haul road ready for the main construction works.
Using a highly-specialised German-built Wirtgen WR250 soil stabiliser, O’Keefe has mixed approximately 1,500 tonnes of cement into the sandy soil and spread a 150mm layer of crushed concrete over the top.
Soil stabilisation, using either lime or cement, is a well-proven method of transforming unstable cohesive soils into a stiff granular texture capable of bearing dynamic and static loads.
Brian Doogue, O’Keefe’s Soil Contracts manager, explains: “Cement stabilisation allows us to use site-won material rather than bring in thousands of tonnes of expensive aggregate. It’s cheaper and more environmentally friendly.
“We built the haul road to a precise design, with a camber in the middle to shed water. The road consists of cement-stabilised soil to a depth of 300mm with a layer of crushed concrete bringing the total depth to 450mm,” adds Mr Doogue.
Preparatory works began last year with site visits and the testing of soil samples. O’Keefe’s soil engineering specialists then designed a mix to suit the site conditions.
“There was no water supply on site, but we’re right by the sea, so we designed a recipe that can cope with the salt in the water,” explains Mr Doogue.
Work on the soil improvement began in late May 2023 and was completed in mid-July 2023 some two weeks ahead of schedule. Besides the Wirtgen machine, O’Keefe used an articulated dump truck to carry materials and a Caterpillar D6 bulldozer with GPS machine control to profile and level the road surface.
The finished surface was compacted with a 16-tonne single-drum vibrating roller.
“We finished the works ahead of schedule. O’Keefe has a strong track record in this type of work – we’ve been doing it for more than 20 years. This project demonstrates how our stabilisation and earthworks teams can deliver a nationwide service," he concludes.