Design of the new pedestrian and cycleway bridge in Strabane, Northern Ireland

Abstract

The new pedestrian and cycleway crossing of the River Mourne in Strabane, Northern Ireland is a slender lightweight cable-stayed structure. The bridge is 96 m long in total, with a main span of 80 m. The bridge is characterised by its inclined main tower, curved in elevation and very slender deck profile. This bridge was designed in such a manner to avoid the use of proprietary damping systems that can be employed to avoid the risk of exceedance of serviceability criteria in similar structures with a view to minimising maintenance costs during the life of the structure. This was achieved using careful dynamic analysis of the structure, wind tunnel testing as well as post-construction testing to validate criteria not explicitly dealt with by the codes of practice. This paper describes analysis and testing undertaken for the dynamic design of this bridge resulting in the client's vision being realised.

Editorial

“…Giaccio et al (2017) found that they could not demonstrate code compliance for overlapping frequencies between the deck and the cables on a steel cable stayed pedestrian/cycle bridge owing to non-prescriptive code provisions. They present their solution to the problem, which employed site data acquisition from velocity meters to ascertain cable damping ratios, which demonstrated code compliance.…”