Royal Warwick Square basement design complete…

Our Leeds office are pleased to have completed the design of the large double level basement in Kensington, with just the final few reinforcement drawings to complete at ground level.

Manhire Associates have been working on the development dating back to 2011 when Squire and Partners were commissioned to progress conceptual designs to closely follow the principles set out in the practice’s Warwick Road masterplan, which was adopted by The Royal Borough of Kensington & Chelsea in 2008.

The engineering of the basement and foundations wasn’t straightforward - St Edwards came to Manhire Associates in early 2017 to explore the possibility of changing the foundations for the second phase of basement construction from piles to raft foundations to allow for future flexibility. Raft foundations offer flexibility in building design and can also offer program and cost savings over conventional piled foundations.

The challenge was that the first phase was already constructed on piled foundations with ‘heave void former’ to protect the buildings from the effects of the soil swelling.

Assessing ground movements for these types of problems is complex and requires soil-structure interaction effects to be modelled so that differential effects can be assessed together with the forces and stresses induced in the buildings.

Various options were considered and Manhire Associates were able to engineer a ‘hybrid’ raft with foundations 1.2m thick and a 10m piled ‘transition’ zone between the first and second phases to control differential movements.

Construction is progressing well on site with GCL making the most of the good weather.