Selfridges

A key concern for the client was the need to maintain operational status for the stores with minimal disruption to customer experience and store logistics. Cambell Brown Engineers developed a sequence that formed the basis of the Scudders programme to enable this whilst addressing the issue which arose from the delivery of a project in a structure which had undergone significant alterations over its lifetime, with minimal records available. We developed discrete stage modelling to build a methodology for delivering the works to the basement, ground and first floors, whilst enabling continued operations on the retail levels situated higher in the structure. We understood that the lack of accurate plans and information would present significant challenges to any team undertaking works. To address this we modelled all the information that we did know including the extensive (and previously unmapped) utilities, unusual structural compositions and multiple historic alterations. The temporary work design was then based on ‘envelopes’ that could deal with a large variation in build-ups to ensure flexibility. To effectively move the load from the existing columns to the temporary supports and back on to the permanet columns. This the main supporting columns would induce movement and cracking to the occupied upper levels. Our jacking designs allowed pre-load and pre-deflecting of both the temporary structure prior to demolition and the permanent structure afterwards. The building was carefully monitored during all stages of loading and unloading.