ABSTRACT
There are three concepts used when designing multi-storey steel structures. They are simple design, semi-rigid design and a fully rigid design. The simple design concept assumes that the connections between members will not develop restraint moments and are therefore assumed to be pin jointed. For fully rigid design or continuous construction the loads on members should be arranged in the most unfavourable pattern in order to obtain the maximum/ minimum forces and moments. The method of protection depends upon the fire rating required by the building regulations, cost of protection and ease of erection. There are various methods of fire protection which include: Concrete casing (in situ or precast), Lightweight casing, forming a box around each member, Suspended ceilings and Applied coatings often sprayed around the profile of the member.
