Page 16

0603NSCMarch06

Commercial Car park ramps were The job has essentially been a logistics exercise for and we have got to work around each other.” delivered as 18m long pre Bourne, working with main contractor Costain. The Erection of the steelwork is now nearing comple- fabricated pieces five storey, steel framed car park is on the critical path tion and the PalaceXchange is currently on schedule and has been built up in full height sections with re- for its October opening. The retail accommodation is inforced concrete filled Circular Hollow Section (CHS) of two and three storey structures with storeys vary- columns. All of the steelwork is being delivered to a ing between 2m and 6m in height. The steel frame of busy urban area to a sched- the northernmost building weighs 310t and consists “The logistics of ule carefully managed by of 2260 pieces of steel and 7415m2 of composite metal the project are Costain and Bourne. But deck flooring erected in 10 construction phases. The the CHS columns require southern building has a smaller floor area of 5130m2 very important.” particular attention. After and consists of fewer pieces – 1378 – but is a heavier fabrication, shot blasting structure at 434t. and painting at Bourne’s yard in Poole in Dorset, they “The steel frames are a fairly simple design, with travel north in 18m lengths for filling by Tarmac in columns typically 254 UC 89 in the North frame and Derbyshire, before being transported back down to floor beams up to 610 x 229 UB 113. It’s fairly light Enfield at the correct time. stuff, but coordination of the fabrication, delivery and “The logistics of the project are very important,” erection has been critical to the overall construction says Bourne Steel Divisional Manager Nick Flexen- programme,” Mr Flexen-Cook says. Cook. “The CHS columns have to be fabricated early Bourne is due to complete its work at the end of for preparation, concrete-filling, shot-blasting and March this year and now just has steelwork of the Requirements for the car painting before getting to site, plus there are concrete car park and civic building to finish off. The erection park and a tight construc- stair and floor units to go in at the same time. Planning of the car park started in October last year. Bourne tion programme resulted in is being carried out in close cooperation with Costain has operated on two work fronts in tandem, working selection of steel because we have occupied the site at the same time out from the building’s four cores with two crawler cranes. Columns have been built on a large 12m grid, with 300mm deep hollow-core pre cast planks span- ning between the asymetric beams. The car park steelwork weighs 1482t and consists of 1703 pieces including the eight ramps between floors. The ramps were delivered to site as 13 pre fabricated, 18m long pieces. Each consists of steel lattice trusses forming the structural depth and the ramps’ barriers either side of pre cast concrete road- ways. All of the structure is above the roadway, so no downstand interferes with headroom below. And an onerous 150kN restraint specification has been met with the steelwork barriers. “The car park is the dominant feature,” says Gif- ford’s James Miller. “It is possible to build ugly car parks, but the PalaceXchange structure will have a slender appearance, alongside the glass fronted civ- ic facility which will wrap around one corner of the building. Cladding has been chosen carefully and will be Cedar from sustainable sources.” 16 NSC March 2006


0603NSCMarch06
To see the actual publication please follow the link above