A Polyester-Rope Suspended Footbridge in Ait Bayoud, Morocco
Structural Analysis and Key Details
Edward M. Segal
Theodore P. Zoli
|Conference:||Footbridge 2017 Berlin - Tell A Story, 6-8.9.2017, Technische Universität Berlin (TU Berlin)|
|Published in:||Footbridge 2017 Berlin - Tell A Story|
This paper describes the analysis and structural details for a 64 m span polyester-rope suspended footbridge
built in 2013 in rural Ait Bayoud, Morocco to provide members of the community with year-round access to a
health clinic, school, and local markets. Polyester rope is an engineered, load rated product designed to
endure rough handling and extreme weather. Although this product is frequently used in marine and arboreal
applications, it has been rarely used in structural engineering applications. This is the first bridge at a
significant scale that uses polyester rope in place of typical steel wire rope.
The first objective is to present the nonlinear static structural analysis of the bridge. Due to polyester rope’s viscoelastic behavior lower-bound and upper-bound material stiffness models are considered. No deflection criterion is required in this remote area, so the bridge is theoretically allowed to deflect significantly under full service loads. Practically, these deflections result in onerous walking slopes that are intended to limit the live loads that are ever applied to the bridge at a single time. The second objective is to present the key details at the backstay anchorages and tower saddles. These details take into account large rope elongations that arise during bridge construction and use. Constructability, adjustability, and longevity of these details are discussed.
|Keywords:||structural design, structural analysis, polyester rope, suspended bridge, geometric nonlinearity, low stiffness|