Philippe Van Bogaert
Gilles Van Staen
Hans De Backer
Abstract
Historic and archaeological sites are often subjected to harmful environmental as well as human factors. Covering these sites with protective structures or shelters does not always render the desired result, since the authentic character of the site may be impaired. By building walkable covers above the area, social interest in historic remains can be promoted, as visitors can observe them from above without intruding activity or influence the ambient conditions. In addition, these walkways can be equipped with lateral cables to shift foils above the site, whenever visits are prevented by the weather. The aim of the study is to determine which are the detrimental loads and effects on such light structures. Firts three typologies of adapted footbridges are introduced. For each type, requirements of strength, stability, human induced vibration and effects of wind, including vortex are being verified. From these developments clearly results that vortex shedding is the most critical condition, albeit simple adequate systems can be installed for mitigating this detrimental effect. Hence, future improvements should emphasize on improving torsion stiffness or, as an alternative, including multiple connections, such as in cable structures.
Keywords
Heritage sites, footbridges, vortex shedding, human induced vibrations, light structures.