Keller's cliff stabilization scheme for Scarborough Spa Featured

Keller helped provide a solution to stabilize a cliff face and protect an iconic building in North Yorkshire, UK.

The historic building is known as the Scarborough Spa. It is a Grade II listed building in South Bay, Scarborough, North Yorkshire, and is used as an event and entertainment venue. A cliff behind the building was prone to future failure and therefore stabilization works needed to be conducted.

Working with Balfour Beatty, Keller helped provide a solution to stabilize the cliff face and protect the iconic building from potential damage and future ground movement. Keller proposed installing piles to provide support by tying into the underlying competent rock and restrain the lateral forces which were causing the instability.

To dissipate the loads, a detailed moment analysis was performed by the project engineers which determined a lateral load of 1500kNm at peak. Each pile required a minimum rock socket or penetration into the underlying rock which varied in depths from 20 to 35m. This needed to be installed in restricted access and working room conditions while still maintaining a safe working practice, ongoing site operations, and interaction with other works.

The final solution decided upon was the installation of 205No 406/340mm diameter piles to depths of up to 35m reinforced with 304mm diameter OD x 22m wall bespoke milled steel tube in sections with fully tested and certified joints to allow the bending moment to achieve the necessary restraint for the lateral forces to be achieved. The work was carried out between November 2018 and May 2019.