Figure 6: Elevation
3.4 Walkway
The walkway is carried by double angle steel crossbeams
spaced every 1m. The crossbeams are supported by steel
reinforcing bar suspenders, which transmit the load to
the main cables. The deck surface is made of planks of a
local tropical hardwood with superb durability.
A safety mesh fencing is attached between suspenders
and anchored to the side of the deck planks on the
bottom and a hand rail cable on the top.
3.5 Lateral Stabilization
Cable suspended footbridges tend to be very light
structures with susceptibility to large vibrations and
sway. The self-weight of the walkway surface is only 20%
of the total design load. Furthermore, the long span and
high design wind speeds contribute to a large lateral load
on the bridge. To improve serviceability with reduced
sway and alleviate lateral loads on the towers, a cable
wind guy system was designed (see Figure 8 below).
The geometry of the wind guy cable for the Arenales
Bridge was challenging due to the local topography. An
efficient layout was made possible using custom
anchorages and spanning over a river tributary on the
southwest corner of the site.
Figure 7: Walkway section
Figure 8: Plan
3/2017