The Clarges Mayfair development is a 18,580m2 landmark mixed-use scheme consisting of four buildings A, B, C and D. The high-end residential Block A, on Piccadilly, is a ten-storey concrete-framed building with three levels of basement.
A top-down construction method was adopted on Block A, where the B1 level was the base slab for the top-level construction. The method that was adopted required the B2 slab to be cast on prepared ground and then the B1 transfer slab to be cast directly on top. The B2 slab was then temporarily supported by stressed Macalloy bars prior to the completion of the excavation to B3 level. Upon completion the B2 slab was then lowered from the B1 level using strand jacks at various locations on the slab. A synchronous hydraulic system was then used to lower the slab ensuring that loads and levels between each jacking point were within predicted and servicability limits.
This new way of constructing as part of the top-down methodology allowed the excavation to be completed faster than would typically be seen with top-down construction with each level cast as you progress down.
This innovative solution from Praeter Engineering won the Post-Tensioning Association’s 2016 Best Project catergory and further information on this can be found in the following link here