Optimum design of steel portal frames

Abstract

The pitched roof. single bay, steel portal frame is now, a conunon structural form for single storey industrial buildings in Sri Lanka. It is adopted in preference to the conventional form of roof truss-stanchion or lattice girder-stanchion, type of steel building. Portal frames consist of pinned base or fixed base stanchions with rafters rigidly connected at the eaves. Hot rolled Universal Beam sections are used for stanchions and rafters. Haunches are often adopted at the eaves and apex to provide a greater moment carrying capacity. The relative ease of fabrication. the speed of erection of such frames and the effective use of space within this type of structure have led to its increased use as a structural form for industrial buildings.