Vibration Control of Pedestrian Bridges

Abstract

In the last years, a wide number of footbridges have been

built as demand response of more direct pathways in

cities. These structures have lower building requirements

as compared with standard bridges. This circumstance has

facilitated the development of new structural design with

complex geometries and innovative materials. As a result,

these structures may be slender, light and low damped,

leading to vibration problems once in service. The current

codes take into account this problem, and recommend designs

with natural frequencies away from the typical pedestrian

pacing rates and fi x comfort limits to guarantee the

serviceability of the structure.

This paper studies this problem from a practical point of view.

Thus, the key points of codes and footbridges guidelines

are showed, the typical experimental dynamic analysis

techniques are presented, and the usual solutions adopted

to improve the dynamic performance of these structures are

discussed. Finally, the works carried out on the Valladolid

Science Museum Footbridge by Centro Tecnológico CARTIF in

collaboration with the Universities of Valladolid and Castilla

La Mancha are showed. These works include: (1) the dynamic

study of the three steel spans of the footbridge, (2) the design

and implementation of a tuned mass damper in the liveliest

span, (3) the implementation of an active mass damper using

an electrodynamic shaker, and (4) the development of fi eld

tests to assess the serviceability of such span.