Steel Buildings in Europe

Part 1: Architect’s Guide 1 - 14 25 - 40 m 6 m 6° 6 m 25-30 m (a) Portal frame – medium span (b) Curved portal frame 8 m 8 m 9 m 8 m 3.5 m 25 m 8 m 6° (c) Portal frame with mezzanine floor (d) Portal frame with overhead crane 25 m 6 m 6° (e) Two bay portal frame 10 m 8 m 3.5 m 6° 6° (f) Portal frame with integral office 40 m 6 m 10° 3.00° (g) Mansard portal frame Figure 3.2 Forms of portal frame Portal frames typically have straight rafters, as shown in Figure 3.3. The same structural principles can be followed to form a portal frame with a curved rafter, as shown in Figure 3.4. In each case, the connection of the rafter to the column is substantial, and usually the rafter is haunched locally to the column. The dimensions of the haunch should be allowed for when considering the clear height requirements.