BHC Ltd were awarded the Steelwork Subcontract for the new, state-of-the-art and blast resistant INEOS Olefins & Polymers UK headquarters.
The construction of the new headquarters located within a large petrochemical works brought forward a host of unique challenges, the most important challenge to overcome was ensuring the building was blast resistant. In the event of an accident involving combustive materials, the building was designed to withstand any possible resultant blasts.
The steel frame had to be ductile in the event of a blast, this led to the decision of using steel framed cores for the building instead of a more ridged concrete core. All of the bracing within the building comprises of 250mm x 12mm flat sections which were used as it would offer more flexibility.
The only area of the building that did not require flexibility were the connections between the cross bracing and the main frame’s columns. Here the large stiffened connections were used.
Precast piles to a depth of between 35m and 40m were installed prior to BHC beginning the steel erection programme. The steelwork formed a braced frame that followed a regular pattern of 7.5m x 18m. A series of 18m x 750mm deep cellular beams were used throughout the structure to create an open plan space. The beams were the heaviest and longest steel sections erected and weighed approximately 5.5 tonnes each. BHC began by erecting the central area of the building which contained the main core, when this was stable, the erection team was divided into two groups to work outwards in both directions simultaneously.
The entire steel frame was erected using two 80 tonnes mobile cranes. BHC were also responsible for the installation of the metal decking and the precast stairs.
All intumescent painting has been carried out by BHC offsite at its fabrication yard. Again for blast resistance, the paint specified for this building is of a higher specification than usually applied to commercial structures.
