52 Lime Street Aspects of Basement and Piled Foundation Design and Comparison with Monitoring Data

The site at 52 Lime St in the City of London has been redeveloped by WRBC Development UK Limited. The development comprises a 35 storey office tower with two basement levels generally and a 3 level basement on the west side. Piled foundations and retaining walls were required. The basement extends up to the party walls with adjacent structures. Collaboration between Design and Construction parties on construction sequence and temporary works was key to the success of the project. A soil structure interaction 3D finite element analysis was carried out to model behaviour of the structure and surrounding ground movements, which also ensured the success of party wall approvals. Out of balance earth pressures and lateral loads from restraint to the core added additional complexity to the design and construction. A very unusual alluvial soil infill feature was observed on this site, not previously found on other City of London sites. The paper discusses the key design and construction features of the 52 Lime St basement and foundations and the comparison of design and measured movements.