Tembec needed to build a bridge to forest operations that supply its sawmill at Béarn, Quebec. 

The requirement was a bridge on a 2-way road over the Albert River in the Témiscamingue region. Several constraints had to be met.

Among those were the width of the river (12 m / 39 ft.) and the load on the trucks that would be crossing. This is a forestry road with intensive truck traffic and the structure needed to support heavy loads. Time was also critical because hauling wood had to start as soon as possible. Another factor was cost - Tembec needed a technically sound but also economical solution.

 

Armtec proposed and supplied a low profile arch Bridge-Plate. easy and fast to install and the lowest cost solution compared to other options such as concrete bridges.

Dimensions for this project were a 13990mm (550.78 in.) span with a 4220mm (166.14 in.) rise and 12.080m (39.63 ft.)length. The crown was 6.0mm (.236 in.)thick and the haunches and sides were 7.0mm (.275 in.).

"Every design is made to respond to several constraints such as live loading and height of cover," explains Edy Barhoum, Armtec's technical representative who handled the project. "For this one, live loading was taken as L-100 for forestry trucks. We have different shapes, different thickness to be taken into consideration, plus the minimum height of cover to keep the road profile as is."

Bridge-Plate is made of galvanized steel with the deepest and strongest corrugation in the market today (400 x 150mm / 15.74 x 5.9 in), enabling long span soil structures to be built more economically than ever before. It is assembled from lightweight sectional plates 1.2m (3.9 ft.) long weighing about 226.8 kg (500 lbs.) each. In this case 70 plates were used for a total span of 12.8m (42 ft.). The plates are bolted together, making installation economical, simple and rapid.

The bridge took approximately four days to assemble and Tembec Industries handled their own installation. Recommended backfill to be used with this type of installation is granular with angular grains, and material should be graded with maximum particle size not to exceed 75 mm. (2.9 in.) Each layer needs to be compacted to a minimum of 95% standard proctor density.

The Armtec solution offered multiple advantages for this northern site. Designed to withstand temperature variations and the effects of ice and snow, the all-steel construction absorbs any expansion and contraction with no danger of cracking. Bridge-Plate also comes in customizable dimensions and is manufactured in Guelph, Ontario in a high quality-controlled plant environment. The lightweight steel plates result in lower transportation fees and require smaller installation equipment, reducing installation time and cost. In addition, the galvanized finish of the plates is environmentally friendly.