Special Projects Schreyer Award and Award of Excellence
Trans-Canada Highway Avalanche Mitigation McElhanney
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An unprecedented system Under Parks Canada Agency’s oversight, McElhanney—serving as prime consultant—partnered with Dynamic Avalanche Consulting to develop a new avalanche mitigation project along 43.8 km of the Trans-Canada Highway through Glacier National Park. The project began with an analysis of the existing avalanche program and identification of priority mitigations. The process also involved environmental and cultural resource considerations, unique procurement practices and construction management in challenging environments. McElhanney and its partners planned, designed, prepared the tender for and oversaw the construction of 2 km of snow nets, which mitigate avalanches in three critical paths. There were no applicable North American design standards for these nets, so the team turned to Swiss guidelines. The netting prevents snow in the start zone from releasing and causing an avalanche, thus removing the need for active control. These nets are now a leading 16
CANADIAN CONSULTING ENGINEER
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A remote avalanche control system (RACS) at the east end of the park helps increase the avalanche program’s efficiency.
example of how mitigation can be effective in challenging terrain on a large scale. The team also managed the installation of 13 remote avalanche control systems (RACSs), which use explosives to initiate avalanches in five key paths. This arrangement eliminated the need for Parks Canada Agency and the Canadian Armed Forces to conduct artillery control at the park boundaries. Instead, the setup allowed for concurrent control of these paths with artillery control in other areas. Further, McElhanney managed the design, tender and construction of a 19.5-m high reinforced earthen berm, specifically to reduce the likelihood of glide slab avalanches from reaching the highway and blocking the snow shed portal. To assist in avalanche forecast decision-making, McElhanney investigated infrasound and Doppler radar technology. Infrasound arrays, which can detect the low-frequency soundwaves produced by avalanches, and
PHOTOS COU RT E SY MC E L H A N N EY
lacier National Park, located 650 km east of Vancouver, is home to a unique transportation corridor, combining the Trans-Canada Highway, Canadian Pacific Railway and a concentrated cluster of high-frequency avalanche paths. Parks Canada Agency engaged McElhanney to improve the corridor’s safety and reliability by implementing industry-leading avalanche mitigation measures. These solutions, integrated with an existing, complex avalanche control program, have reduced risk for roadway users and the railway and will help keep Canadians moving year-round.
September/October 2021
2021-10-18 10:14 AM
