cable-stayed, pedestrian swing bridge
Bridge form and
function dictated by site constraints
structure for the MediaCityUK development
MediaCityUK is major development in
Manchester, UK, that provides a new home for the UK's BBC and ITV
broadcasting organisations. It includes general office and retail / leisure space, a hotel, residential apartments,
and a new tram station that links to the city centre. MediaCityUK
Footbridge is a key
the development and spans the Manchester Ship
Canal connecting the Trafford and Salford Quays regions of the city.
Gifford (now part of Ramboll) used LUSAS Bridge analysis software to assist with its design of the footbridge.
MediaCityUK Footbridge is an asymmetric,
cable-stayed, pedestrian swing bridge whose form and function was
dictated by site constraints. The bridge comprises two spans: a main
span, approximately 65m in length, which traverses the shipping
channel of the Canal, and a 18m flared concrete-filled back span that
forms the counterweight to balance the asymmetric spans during
opening. The main span of the deck is supported at 6m centres using
high tensile spiral strand steel cables. A distinctive mast is formed
from a fanned array of individual pylons up to 30m tall that converge
at their base to sit on a steel pedestal. The deck is an internally
stiffened, orthotropic steel box that pivots about the centre of the
9m diameter solid reinforced concrete shaft on the main pier. A large
steel casting welded into the pivot zone of the steelwork deck is
mounted on a slewing bearing which in turn is supported on a
fabricated steel stool structure stressed down to the plant room floor
in the main pier. This arrangement provides vertical support; resists
the overturning moment generated about the horizontal axes and also
provides horizontal restraint during bridge rotation. The main pier
also incorporates a plant room housing the mechanical and electrical
equipment necessary for operating the bridge. When closed the bridge
provides a 4.77m high x 10m wide navigation envelope for small craft.
In its fully open position a navigation channel with a clear width of
48m is provided.
|Twinned ties link
the tops of each mast for
stability. Spherical bearings
at the base of each mast
allow for articulation
provides a practical, yet visually stunning, gateway and
landmark structure in the centre of the MediaCityUK development.
- A paper describing how the
MediaCityUK footbridge was designed was one of the UK's
Institution of Civil Engineers most popular downloads in the past
year. It can be downloaded here.
Other LUSAS Bridge case studies: