Joe is one of our structural engineers and joined us in late 2019. He’s passionate about sustainable design and aims to produce low embodied carbon schemes wherever possible. Outside of work, Joe is a keen runner and climber.
Here he gives us an insight into one of his unique projects – Brighton Road. It’s a Grade II listed building in Purley, Croydon, designed in a Neo-classical style. The building was originally used as a town hall in 1930 and used by the local council up until 2012. At this point the building needed significant repair and was transformed into residential units.
The building is split into four wings around a central courtyard. The front and rear wings have existing basement space, and we have been appointed to extend the basement out beneath the remaining two wings. The challenge is to excavate the new basement space without evicting the residents.
Steel beams and columns will be installed to support the existing building, and so our solution is to use this permanent steelwork as the temporary support during excavation. This removes the need for further additional temporary structures, ultimately saving our client money, reducing the construction programme, and minimising material waste.
To safely excavate the new basement while the building remains occupied requires careful sequencing. Trenches will be dug next to the building in phases to allow the construction of the permanent retaining walls. These walls will then provide access to the next phase of trench excavation towards the centre of the building, allowing for the installation of the permanent steelwork. The steelwork will support the structure while the remainder of the excavation and construction works can take place.
We developed 4D construction phasing of the excavation process and analytical models of the structure to check the stability of the building. We particularly focused on the foundations as the bearing pressure differed during the phases of the construction sequence. Great care was taken to ensure that these pressures did not exceed the given limits.
Brighton Road is currently on site and we’ll bring you updates as and when we have them.