Welford Road, Northampton

Retaining walls are useful in a wide range of scenarios. From coastal defence to highways management and wastewater treatment works, applicable across the energy, commercial, infrastructure, maritime, marine, residential, and rail market sectors, retaining walls are structures designed to restrain soil to a slope that it would not naturally keep to. Where the general public are perhaps most familiar with retaining walls, however, is in residential settings, usually for the use of retaining gardens to mitigate issues with slipping and subsidence.

Over 20 days in September 2023, Aarsleff Ground Engineering installed a 79.2 metre open bore king post wall in Northampton for this exact purpose. The wall was constructed to retain up to 2.2m and was constructed using an open bore method, which utilises 600mm diameter boreholes to found the posts for the wall.

When Aarsleff arrived on site to begin work, we became aware of a number of live services on site. The scheme was already designed to avoid a storm drain and sewer service but we quickly discovered the presence of underground cables intersecting the pile line. This was revealed to be a live BT service and therefore, Aarsleff’s design engineers quickly reacted to adjust the design to suit. The pile line was refined in a way that ensured there was no increase in section size or length of material. This meant that not only were costs limited for materials, but the potential extension of the programme was limited and operational delivery could quickly restart.

Speaking on the project, Zohaib Khan, Project Manager, said, “A very interesting and challenging project where Aarsleff’s design and operational expertise came together to determine solutions across various aspects of the project to meet our client’s needs.”

The project was completed in 20 working days. This is a prime example of Aarsleff’s ability to react to unexpected challenges and solve them in a quick and efficient manner, with minimal effects on cost and programme for our clients.