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Commercial Steel programme benefits from cooperation NSC 17 September 15 Anew Grade A office development has quickly taken shape adjacent to one of the capital’s most famous landmarks – the Monument, which was erected to commemorate the Great Fire of London. Taking the plot formerly occupied by three buildings that were demolished last year, the new structure will offer approximately 8,000m2 office space and a further 460m2 of ground floor retail accommodation. All of the upper floors of this nine-storey structure will accommodate offices, some of which - floors four, five, seven and nine – feature outdoor terraces. Structurally, the building has been designed with a steel frame based around one eccentrically positioned concrete core. Below ground level the structure is founded on concrete raft foundations, while a basement and ground slab have also been formed with concrete. Most of the building is built around a grid pattern offering spans of up to 12m. The spans vary slightly because although The Monument Building is roughly squareshaped in plan to fill up the entire footprint of the plot, the western side of the structure does offer longer spans. “So we could minimise the structural floor zone, and hence maximise the number of floors, a steel-framed option was the best solution for this project,” says Arup Senior Engineer Michael Heywood. “Cellular beams have been used throughout to accommodate services and in this way we’ve been able to get a nine-storey structure on a site with strict planning height restrictions adjacent to the historic Monument.” Steelwork contractor Severfield has fabricated, supplied and erected (see box) 650t of structural steel for the project. Utilising a coordinated multidisciplinary Building Information Modelling (BIM) approach, the project team was able to streamline the design, which in turn helped optimise the steel tonnage to its most efficient amount. “We always propose that all subcontractors use BIM on our projects as it not only optimises the design but it’s also beneficial as it eliminates any clashes and speeds up the programme,” says Skanska Project Director Brian Nunn. Speed of programme is always of importance on any site and, to this end, Skanska decided to install the precast stairs inside of the building’s slip-formed core immediately after it was completed. Having done this work before the steel programme kicked off meant once Severfield did commence work, safe access to the upper floors was already in place, which meant no temporary stairs needed to be installed. Utilising the project’s one tower crane and a The steel erection programme was completed in July, ahead of its planned 20 weeks schedule. Severfield Project Manager Robin Hamill puts this down to the close coordination his company had with Skanska and the other trades, which ensured the steel erection and metal decking installation was carried out as efficiently as possible. “We sat down and started planning the project with Skanska 18 months in advance of steel erection starting,” he explains. Most inner city sites pose logistical challenges when it comes to deliveries. The Monument Building is no different as it is slap bang in the middle of the City of London and bounded by two narrow, but busy streets on two sides and a public square along its main façade. Skanska had been able to get a partial road closure on one of the adjacent streets, which allowed the team to create a delivery and offloading zone, albeit opposite Monument Underground station. All steel deliveries were coordinated and had to be unloaded from 7am onwards when the road closure was in place. Unfortunately, this timing also coincided with the morning rush hour and the team had to deal with the thousands of commuters that regularly exit the station. “We had to ensure the steelwork was quickly and safely unloaded from the trucks and then placed on our laydown areas which had to be within the building’s footprint – in other words on top of the erected frame,” explains Mr Hamill. The new building is adjacent to one of London’s most famous landmarks


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