e-mosty June 2018 American Bridges American Bridges | Page 46

THE STRANDHERD-ARMSTRONG BRIDGE
Project Team
The bridge supports four lanes of traffic, one of which
is dedicated to public transport, and one cycle lane
per direction taking place between the three arches.
Two sidewalks, outside the arches, complete the cross
section. The large width of the deck - 54.7 m
abutment and 58.7 m in the center - is mitigated by
the spaces provided for the passage of the arches,
promoting natural lighting of the banks under the
deck.
Engineer: Harbourside Engineering Consultants
Bridge Designer: Parsons (formerly Delcan)
General Contractor: Horseshoe Hill Construction
Steel Erector: Montacier International
Steel Fabricator: Cherubini Metal Works
Steel Detailer: Tenca Steel Detailing
The Strandherd-Armstrong Bridge, located south of
Ottawa, connects the communities of Riverside-South
and Barrhaven, between Strandherd Road and Earl
Armstrong Street.
This new link promotes the development of these
communities, reducing travel times and improving the
public transport offer. It offers easier access to
services, businesses and jobs, as well as schools and
recreation areas. It also contributes to the
improvement of the Ottawa area network.
The Bridge has a total length of 143 meters and the
arches rise to 21 meters above the roadway and have
a 125-metre opening. The lightness, strength of the
material and its flexible use, permitted aerial launch
work that could not have been implemented.
The environmental objectives and the respect for this
heritage site were certainly governing factors. The
goals were achieved and undoubtedly exceeded, steel
made this exceptional structure possible.
The structure has a total length of 143 m. The arches,
culminating at 21 m above the roadway, have an
opening of 125 m. Each arc is constituted by a lattice
of tubes forming a triangle of 4.25 m wide by 3.50 m
high for the central arc and 3.50 m by 2.50 m for the
lateral arches.
The tubes, 508 mm in diameter, are bent with a radius
of about 90 m. The two upper tubes are
interconnected by spacers "K" and with the bottom
chord by diagonal spacers. These spacers, also in tube,
have a diameter ranging from 219 mm to 273 mm.
On the central hundred meters, these arches support
a mixed deck through twenty-five pairs of lines. With
the exception of the first two and last lines, in tube, all
the others are cables composed of waxed sheathed
galvanized strands, with seven strands for the
suspension of the road parts and four for those of the
bridges.
At the ends, between the last line and the abutment,
the deck is supported by steel columns resting on the
support mass of the arches.
2/2018