INNOVATION-May-June-2020

MCGREGOR SUSPENSION BRIDGE DEMOLITION The McGregor Suspension Bridge was an iconic structure crossing the McGregor River, west of Prince George. It was originally built in 1972 and was designed by Gower and Yeung of New Westminster. Keery Consulting Ltd. was engaged to design the demolition procedure; Platinum Stone Contracting conducted the demolition in the fall of 2019. Platinum Stone believed that the demolition should be conducted without a work bridge or large crane; Keery Consulting developed a 46-step

demolition procedure accordingly. Associated Engineering assisted with the procedure, and modeled the structure for stages of the demolition. The procedure removed the deck and jump spans, then jacked up the main span girders, and installed hillman rollers at each abutment and needle beam. The main span girder train, weighing 180,000 pounds, was then de-launched to the bank of the river. Owner: Ministry of Forests, Lands, Natural Resource Operations and Rural Development (FLNRORD). Participants: FLNRORD: Colton Polsom, P.Eng. Keery Consulting Ltd.: Roy Keery, P.Eng., Alan Zhao, EIT. Associated Engineering Ltd.: Dale Harrison, P.Eng. Platinum Stone Contracting Ltd.: Scott Schols.

PATTULLO BRIDGE SEISMIC EARLY WARNING AND WIND MONITORING SYSTEM The Pattullo Bridge is more than 80 years old and was not designed to meet current wind and seismic loading standards that would apply to a new bridge constructed today. To improve safety for bridge users, TransLink implemented an advance seismic warning and wind monitoring system. The wind warning system will monitor and measure wind speed, and a seismic warning system will sense an earthquake in progress and provide alerts up to one minute prior to damaging ground waves reaching the bridge. The system includes seismic

activity and wind warning sensors; traffic control devices, including traffic gates, traffic signals, and warning signs for bridge users; and communication and monitoring devices to provide warnings and perform closures. Participants: TransLink (Owner): Sany Zein, P.Eng., Susan Chu, P.Eng. PMY Consulting Ltd.: project management. PBX Engineering Ltd.: lead design. COWI North America Ltd.: structural design. Parsons Corporation: feasibility study. Weir-Jones Engineering Consultants Ltd.: seismic warning system. Archer CRM Partnership: archeology. Jemma Scoble and Associates Consulting Inc.: First Nations consultation. Hatfield Consultants: Environmental.

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