A major requirement of General Motors (GM) was 3D modelling of all disciplines to strict GM standards. The design model needed to be displayed over the internet in weekly teleconferences, at which design issues were discussed with GM facility and process engineers located in India and the United States.
Through the utilisation of BIM modelling, Aurecon was able to ensure that all of the 2D documentation produced from the 3D model remained clash free.
A roof top substation was a significant design challenge, due to the long, 20 metre spans and loads associated with four 3 500 kVA transformers mounted on the roof. Using BIM, it was possible to optimise design and function to meet both structural and operational requirements. Ten air handling units were designed to service the space each capable of delivering 13 m3/s of tempered air. The system is fed from a central utility building existing on the site via a 1.5k m chilled water pipeline, capable of transporting up to 340 L/s of chilled water and included compressed air and service water feeds.
Within the plant itself the services are reticulated entirely through the truss space, so as not to clash with process equipment. Electrical services run from an existing primary substation and are delivered to a new substation on the roof of the building. The new process equipment is serviced by bus duct reticulated through the truss space. All other services were required to be outside a 1.5 m2 exclusion zone around the bus duct.
A grid type fire suppression system was designed in 3D and fed from a new ring main that ties into an existing site service. Significant time was saved as the 3D modelling used ensured the existing site services and new systems, including communication and fire alarm, primary cable, fire protection and drainage, were coordinated within the design and remained clash free.
The civil works package involved cut and fill of a brown field site on the facility and included new areas of car park and new roads servicing the main delivery and receiving areas to the north and south of the building. Slab on grade with concrete columns and steel trusses were designed as the structural elements.