Basement Retaining Wall & Bearing Piling – Golders Green, London
All piling works were carried out in accordance with the ICE Specification for Piling and Embedded Retaining Walls, ensuring full compliance with recognised industry standards for safety, structural performance and temporary works stability.
Contiguous Pile Retaining Wall
A total of 163 contiguous piles were installed to form the basement retaining wall. Each pile was constructed at 350mm diameter and to a depth of 8 metres. During the temporary works stage, the retaining wall was designed to act as a free-standing cantilever structure. In the permanent condition, restraint is provided by the completed basement slab and ground floor slab, ensuring long-term wall stability.
Bearing Piles
In addition to the retaining wall system, 56 open-bored bearing piles were installed, also at 350mm diameter. These piles were concreted and reinforced to approximately 1 metre above the proposed basement slab level, with the remaining bore backfilled using pea gravel and sand up to piling mat level, in accordance with the structural design and sequencing requirements.
Programme & Productivity
The piling works were completed ahead of schedule, with a total of 219 piles installed in less than three weeks. Daily output increased significantly from 12–14 piles per day at the start of the programme to 18–20 piles per day following full mobilisation. Strong site logistics, technical coordination and efficient working methods enabled the main contractor to recover up to one week on the planned piling programme.
Site Challenges & Ground Preparation
During the works, remnants of existing foundations were identified and removed safely, exposing the underlying natural ground profile. Excavated material was replaced with suitable engineered fill to maintain a stable working platform and achieve the required formation levels.
Soil removal and muck-away operations were carefully phased to maintain uninterrupted access for concrete deliveries and avoid delays during pile construction and pouring operations. This coordination was essential to maintaining production rates and ensuring consistent quality across the entire basement piling package.
This project demonstrates our capability in delivering contiguous piled retaining walls, basement piling systems and bearing pile foundations in London Clay conditions, combining programme efficiency with strict compliance and high installation quality.