King’s Cross is one of London’s most important stations, offering train services to many parts of England and also Scotland. There is also a large underground station below. In the course of redevelopment and expansion, the new western concourse alongside the station, which is protected by a conservation order, has been roofed over by an almost 9,000 sqm freestanding shell structure. In addition to satisfying normal structural criteria, this complex project, which has been finished in time for the London Olympics in 2012, also comply with strict bomb-blast requirements.
seele constructed a vast steel-and-glass structure next to the station within 12 months, directly above the extremely busy underground station and under difficult erection conditions. Some 1,200 t of steel, mounted on the central “funnel” and 16 tree columns, create a huge half-shell. The radial beams made from welded box sections, with wall thicknesses of 8–20 mm, together with the intermediate diagonals made from circular hollow sections, form a shallow curving lattice. Above the triangles with external dimensions of up to 3.3 or 6.2 m there is an aluminium secondary structure with fully glazed infill panels around the perimeter and above the “funnel”, metal panels elsewhere.
Systematic design with the 3D program “Pro E” has resulted in an extremely short construction time and also guarantees the high precision so essential for such a project. Furthermore, such a method enables the fabrication drawings to be optimised and the number of fabrication operations to be substantially reduced. The positions of prefabricated ladder elements have been exactly set out and supported by a scaffold structure. Starting with the “funnel”, the elements have been tack-welded to spot-welded diagonal members and afterwards welded together. Covered with glass and metal panels with concealed fixings and with all joints sealed with silicone, the result is a delicate half-shell – and a new landmark for London.
http://www.youtube.com/watch?v=7fv_Q7nW_Xc
© Bilder: Vinci