Big R Bridge recently collaborated on an interesting rail tunnel project with our AIL Group sister company in Canada, Atlantic Industries Limited (AIL).
A Canadian Pacific (CP) tunnel for the K+S Potash Canada (KSPC) mine in southern Saskatchewan is the first Canadian installation of a Super•Cor Round structure with our patented MSE-reinforced bevels.
Innovation saves time and money
This innovation allowed construction of the tunnel’s 48′ long (2.5H:1V) bevels without the need for internal bracing during the backfill process. This saved time and money compared to the traditional false-work brace method. Our unique design connects heavy-duty welded wire soil reinforcement mats to a series of connection anchor strips that are integrated with the exterior sides.
AIL’s scope on this project included the structural design of the Super•Cor tunnel and the cast-in-place concrete collars on the bevelled ends. These collars helped stiffen the ends of the tunnel and facilitate grading of the embankment slopes to the tunnel opening. The tunnel construction took place in a 43′ deep cut excavation area, as the completed tunnel would run under a two-lane rural road.
Mid-construction change required swift action
Typically AIL manufactures all Canadian Super•Cor at their Ayr, Ontario plant. Part way through construction it was decided to lengthen the tunnel by 93′ to accommodate a revised site layout. To lessen the impact on the construction schedule, manufacturing of the extension components was shifted to Big R Bridge. The new Super•Cor components were rushed from Big R’s Texas plant to Saskatchewan without severely impacting the schedule. The AIL Group’s consistent manufacturing quality control program ensured easy fit-up between the Canadian and US produced plates.
Pre-shaped bedding and flowable fill save time and money
AIL offered technical assistance on constructing a pre-shaped pipe bedding and on injecting a cementitious, flowable fill under the tunnel invert once the plate assembly was complete. Using flowable material allowed for a faster and safer fill of any potential voids and saved days of hand tamping gravel below the invert.
AIL Mining Engineer provided site supervision
An AIL Engineer was retained by the Contactor, Kelly Panteluk Construction Limited (KPCL), to be on-site to offer part-time assistance during the plate assembly and on two other multi-day visits to assist with the backfill process for the MSE mat layout and shape monitoring. 24/7 technical assistance was also offered over the phone. Both KPCL and their Plate Assembly Contractor, Connal Enterprises, were excellent to work with.
Full-time construction monitoring was provided by the Construction and Geotechnical Consultants, Clifton Associates, including geotechnical engineering, materials testing, shape monitoring and construction field reviews.
Early collaboration helps ensure successful outcomes
This project started years earlier with AIL’s early design/specification collaborations with Hatch, the project’s Design Consultants. The AIL Group encourages this type of early design collaboration, as it helps ensure the most successful project outcomes.
Custom-built rail cars make first trip on new line
AIL Representatives were on-hand on March 13, 2017 as the first 177 of 531 custom-built rail cars arrived at the mine site — enough to complete one of three trains that CP will use to transport KSPC’s product to its world-class potash handling and storage facility in Port Moody, B.C. The first train travelled along 19 miles of CP’s recently constructed Belle Plaine subdivision, connecting its main line with KSPC’s new industrial spur. The tunnel is located on the CP section.