INNOVATION May-June 2018

Project Highlights •

BRIDGE SUBSTRUCTURE STRENGTHENING

AND SUPERSTRUCTURE REPLACEMENT The Fort Nelson River Bridge crosses the Fort Nelson River on Liard Highway approximately 90 kilometres south of the Northwest Territories border. The BC Ministry of Transportation and Infrastructure required a transformation of the original 430-metre-long, single-lane wood-decked Acrow bridge constructed in 1984 into a modern two-lane composite steel-girder bridge. McElhanney Consulting Services Limited commenced design of the substructure strengthening and eight-span superstructure replacement in late 2013. Construction started in early 2016 and was completed in fall 2017. Unique aspects of the project included construction of temporary foundations and the lateral move of the existing Acrow bridge to a downstream detour alignment to allow construction of the new superstructure on the existing strengthened piers and abutments. To accelerate construction, the three lines of girders were incrementally launched into position prior to the deck and parapets being cast. Tim Stevens, P.Eng., Raj Singh, P.Eng., Chad Amiel, P.Eng., C.P. Rebel, P.Eng. Autonomous exploration of the world’s oceans took a step forward in 2017 through the participation of BC subsea company Ocean Floor Geophysics (OFG) in the Shell Ocean Discovery XPRIZE. OFG’s HUGIN autonomous underwater vehicle (AUV) Chercheur and the OFG AUV operations team contributed to a world first by successfully demonstrating an AUV launch, a high-resolution sea-floor mapping survey, and an AUV recovery using an uncrewed surface vessel as the mothership. OFG was part of the GEBCO-NF Alumni Team that completed the XPRIZE Round 1 competition with a stunning array of high-resolution acoustic images and bathymetry products collected by the AUV’s multibeam and synthetic aperture sonar systems. In the photo, Chercheur makes its final approach to the AUV after completing a sea-floor survey. Alison Proctor, EIT, TonyWass, P.Eng., Peter Kowalczyk, P.Geo., Brian Claus, EIT, KarenWeitemeyer, P.Geo., Boris Lum, P.Geo. Photo: Alex DeCiccio, Inner Space Center. AUTONOMOUS RECOVERY OF AN AUTONOMOUS UNDERWATER VEHICLE

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