Steel Buildings in Europe

Part 2: Concept Design 2 - 20 3.4 Kings Place, Kings Cross, London Figure 3.6 Kings Place during construction Kings Place in north London provid es seven floors of office space, a 42 0 seat concert hall, art galleries and restaura nts. The basem ent levels house the auditorium and other reci tal facilities. It is s hown in Figure 3.6 during construction. The flexible use structure is d esigned as a steel-composite frame consisting of 12 m span fabricated beams with multip le circu lar openings and supporting a 130 m deep composite slab. In some areas, the composite floor is supported on a shelf angle. The forms of construction are shown in Figure 3.7. A novel part of the design was the fire engineering strategy, which demonstrated tha t th e f ire re sistance of 90 minutes coul d be achieved by intumescent coatings o nly on the beam s connecting d irectly to th e c olumns; other beams were unprotected. The colum ns were protected by two layers of boards. The long span fabricated beam s are typically 600 mm deep and consist of m ultiple 375 mm deep open ings. The 13 0 mm deep com posite slab is reinforced according to fire engin eering principles which perm it development of membrane effects in fire. The primary and secondary beams connecting to the co lumns are p rotected by 1,6 mm thick intum escent coating that was applied off-site to speed up the construction process. T he coating was a pplied in a sing le layer, whic h was achieved by designing slightly heavier stee l sections to reduce the load ratio in fire conditions. This holistic design a pproach was justified using a finite element model in which the properties of the steel and concrete were modified for the tem peratures in both a stand ard fire and nat ural fi re concept using the fire load and ventilation conditions established for the building use.