Spire London will be a landmark development at the western end of the North Dock within West India Quay. The development will deliver high quality homes in a mixture of tenures and will rise up to 67 storeys in height. Key project challenges included Crossrail tunnels passing directly below the building footprint, a 10m deep basement abutting a listed dock wall, and extremely high foundation loads. RBG developed a basement construction sequence that minimised programme and material costs whilst remaining sufficiently robust to control ground movements within the surrounding area.
RBG’s technical solutions included a 4m thick piled raft spanning 14.5m over the Crossrail exclusion zone. To achieve the extremely high required foundation capacities, piles of up to 2100mm in diameter extended to 70m below ground level into the underlying Grade A Chalk. Ground-structure 3D finite element modelling was used to optimise the foundation solution which included reducing the lengths of many of the piles by up to 20%. To validate the pile design, two preliminary load tests using Osterberg cells were constructed and loaded to failure or the limit of the load cells. The final load was jacked into the piles before the cells exceeded limiting movements was 108MN, a new UK record for state pile testing. In partnership with Bachy Soletanche, RBG won a Ground Engineering Award for this achievement in 2018. RBG’s considerable experience of gaining approvals from third parties combined with the high-end methods of analysis used ensured that there was no delay to the project due to the interface with the tunnels, nearby dock wall or surrounding buildings. RBG also contributed to the development of a holistic monitoring regime for the tunnels and above ground assets.
RBG Geotechnical Services:
- Ground investigation works,
- Complex piled foundation,
- Pile testing,
- Site supervision,
- 2&3D FE modelling,
- Ground movement and impact assessments,
- Ground stability,
- Liaison with third parties,
- Prop design,
- Monitoring of tunnels and existing buildings.