Steel Buildings in Europe

Part 2: Concept Design 2 - 33 Figure 3.23 Quasi- curved portal frame 3.6.6 Multi bay portal frame Multi-bay portal frames may be designed by using intermediate columns, as shown in Figure 3.24. If the number of internal columns must be minimised it is possible to remove every second internal column, or to only leave one internal column every third frame. Where the internal column is removed, a deep beam (often known as a “valley” beam) is designed to span between the remaining columns. Continuity of the rafters is achieved by using a haunch connection to the valley beam, as shown in Figure 3.25. Figure 3.24 Multi-bay portal frame