Putting Vimy Ridge Memorial Site on solid ground
Students who enroll in the undergrad course in rock engineering taught by Prof. Jean Hutchinson (Geological Sciences and Geological Engineering) are getting a bonus: lessons in WWI military strategy. Doing so helps them understand Hutchinson’s role in a project that has stabilized the ground surrounding the Canadian National Vimy Memorial on the highest point on Vimy Ridge.
Officials at Veterans Affairs Canada were concerned about the safety of visitors and workers employed at the memorial site, and so in 2001 they hired a consulting firm to assess the risk of ground subsidence – sinking or even caving in.
Hutchinson, on faculty at the University of Waterloo at the time, was consulted because she’s an expert on ground subsidence and the geomechanics of mine closures. When she joined the Department of Geological Sciences and Geological Engineering here at Queen’s in 2001, she brought along her work on the project.
The Vimy memorial site in northern France consists of the memorial itself, an Interpretive Centre, restored Allied and German trenches, a section of rehabilitated tunnel, and two cemeteries.
“The excavations at the site include trenches, tunnels, dugouts, headquarters and hospitals. On the Canadian Corps Vimy front line alone, 10 km of tunnels were dug,” says Hutchinson. She adds that it would have been impossible to understand the geomechanics of the site without a knowledge of the nature of WWI-era warfare.
“Many people aren’t aware that trench warfare involved attacking enemy defences by using military mines,” she says. “Below all of these excavations is a further labyrinth of tunnels created by enemy miners – sappers – and craters caused by massive amounts of exploded ordnance.”
In advance of the Vimy restoration work, the site’s administrators were concerned about the stability of roads and parking lots, as well as the safety of visitors who were touring the battlefield site. The consulting project resulted in recommendations for several changes to make the ground safer and more stable. These included reinforcing construction roads with large steel plates; adding reinforced concrete pads in parking areas, and relocating others. The team also designed and implemented a system to map “failure events” in order to help predict where else subsidence might occur.
Several graduate students worked at the site. A master’s student focused on the strength and quality of the chalk, the primary material in the geological setting at Vimy Ridge. A postdoctoral fellow, who’s an expert on carbonate rocks, helped identify and map fossils to determine which layers of chalk are present on Vimy Ridge. This enabled the team to compare the quality and behaviour of the chalk there with observations of failures at specific sites along the white cliffs on both sides of the English Channel.
Hutchinson, who is cross-appointed to the Royal Military College, has talked to alumni Branches about her work at Vimy, and each November she gives a lecture to undergrad classes at both universities speaking about the challenges posed by the project and the lessons that have come out of it.
“The students always comment on how much they learn about military strategy and the contribution of the four Canadian Divisions who fought so valiantly together in April 1917, seizing the heights at Vimy Ridge,” she says.
In addition to reading about 20 volumes on WWI military history, Hutchinson credits the UK-based fraternal organization The Durand Group with helping her understand the ravages to the land at the Canadian National Memorial Vimy Site. The site includes 100 hectares of land granted by the people of France in perpetuity to the people of Canada in recognition of the sacrifice of Canadians during the Great War. The Memorial itself is dedicated to the 66,661 military personnel who died during the war, and the names of the 11,285 Canadians who fell in France and have no known graves are inscribed in the limestone around the monument’s base.
For further information about the geotechnical work at the site and request copies of publications, contact Dr. Hutchinson at firstname.lastname@example.org.