e-mosty June 2018 American Bridges American Bridges | Page 49

box girders covered with reinforced concrete decks.
The superstructure is supported by large reinforced
concrete pillars and reinforced by reinforced concrete
foundations.
The constraints of the valley and existing roads being
unconventional, lead to more challenges and
creativity for the construction of this bridge. In
addition, the superstructure was to be built without
interruption of traffic on the existing bridge or the
provincial highway passing underneath.
Moreover, the size of the beams and the limitations
on the site prevented the use of a large crane under
the bridge.
So, instead of erecting the structure in a conventional
way, the progressive method of launching the beams
was used pushing each of the beams all along what
has already been built.
Completion of the installation of the first beam lasted
59 days throughout the winter. Once this span was in
place, two traffic lanes were opened on the new
structure and the old structure was removed, allowing
the continuity of the circulation throughout the
erection of the second span and the triangular arch.
The 32 beams were assembled sequentially where,
two by two, the beams were bolted together, placed
on the bearings supported by pillars.
Temporary steel towers supporting the structure of
the arch during erection were put in place and then
removed once the project was completed. The very
well-organized erection was made during the night
when the highway below was closed.
ALLUMETTES BRIDGE
This 280-meter long road bridge replaced the
Allumettes Bridge over the Ottawa River main canal
southeast of Pembroke, Ontario, connecting the
province of Ontario and the city of L'Isle-aux-Eaux -
Allumettes, in Quebec.
Project Team
Structural Engineer: Delcan, a PARSONS Company &
DPHV
Project Manager / General Contractor: Pomerleau
The structure, consisting of two box girders cut into
22 segments, comprises 1,880 tonnes of steel
components. The complexity of this project is
characterized by the high weight of box beams up to
91 tonnes and its tight schedule. The bridge was
commissioned in August 2015.
Fabricator: Canam-Ponts, division de Groupe Canam
Detailer: Tenca Steel Detailing Inc.
Erector: Montacier
2/2018