Keller crews spent several months of night shifts installing high capacity rock anchors to reinforce the 5-span truss bridge structure’s resistance to seismic loading.

Originally built as a railway bridge by Canadian Pacific Railway between 1898 and 1901, Alexandra Bridge carries vehicle and pedestrian traffic over the Ottawa River between Ottawa and Hull, Quebec.

Keller crews spent several months of night shifts in 2009 installing high capacity rock anchors to reinforce the 5-span truss bridge structure’s resistance to seismic loading. Drilling was staged from the bridge deck during nightly temporary lane closures.

The heritage masonry portion of the piers was drilled with non-percussive rotary drilling, while the mass concrete and rock portions of each hole were drilled with down-the-hole hammer. All 103 rock anchors consisted of 75mm/1030MPa threadbar tendons grouted into 178mm diameter holes.

Additionally, each anchor was encapsulated in a woven geo-textile bag to prevent loss of grout into inersected fissures and masonry joints. The longest rock anchors, at Pier 2, measured 39 metres from top of pier (45 metres from bridge deck).

With the river doubling as the border between two provinces, Keller incorporated a new company, Les Entrepreneurs Geo-Foundations to perform the half of the project located in Quebec.

Project Facts

Owner

Canadian Pacific Railway

Main Contractor(s)

N/A

Keller Business Unit(s)

Keller Foundations Ltd.

Engineer

N/A

Download Project Sheet

Alexandra Bridge Project Summary