| Popis: |
Until the beginning of the 1980’s, the most widely used metallic structure used in Spain for building bays was a truss structure erected on pillars. Since then, we have seen a tendency towards the use of rigid frames, which is the most common structure at present. Aside from the obvious functional advantages of rigid frames, it is commonly thought that rigid frames are now more economical to build. The purpose of this study is to determine whether rigid frames are actually more economical to build than trusses. For that, we have compared rigid frames and “English” trusses with a series of spans ranging from 10 m to 30 m; and a series of pillar heights from 3 m to 6 m, calculating and evaluating both their metallic structures and the foundations. The following conclusion was reached: when only the cost of the steel structure is considered, a rigid frame is more economical than a truss with spans up to 30 m. However, if foundation costs are also taken into account, the rigid frame is more costly with spans of over 20 m, due to the enormous size of rigid frame foundations. As spans increase, the truss structure becomes much more economical. |
