At Viau, we’re reclaiming and reusing land
The Port of Montreal is spearheading a land recovery and reuse project that’s positioning it as a pioneer in the field.
On the Viau sector work site, the soil encapsulation mobile plant does not pass unnoticed. As high as three or four floors, it swallows up the crushed soils and mixes them with cement, consolidating them. The result is a thick, malleable material that we will spread on the bottom of the excavated ground.
The soil encapsulation mobile factory swallows up the crushed soils and mixes them
with cement to make a thick, malleable material.
The aim of the operation is to solidify this area that covers close to nine hectares, because it’s meant to accommodate containers. To be able to withstand the weight of containers piled three to four high along with lifting equipment and trucks, the ground has to be extremely stable. However, the ground in the Viau sector is too soft for us to solidify simply by compacting it. Normally, we would have extracted 44,000 tonnes of poor soil and replaced it with a noble soil made mainly of crushed stone that we would have brought in from a quarry.
But the Port of Montreal turned to soil encapsulation instead. This new technique allows it to reuse the 44,000 tonnes of poor soil extracted, give it good solidity by mixing it with cement, and then re-deposit it at the bottom of the excavated hole.
By doing so, we will have saved a minimum of 170 tonnes of greenhouse gas emissions!
How to save 170 tonnes of GHG
If we had opted for the traditional method of replacing poor soil with noble soil, we would have had to send the poor soil extracted to a technical landfill site. That would have taken 1,257 return trips by semi-trailer, which would have produced 85 tonnes of greenhouse gas emissions. Transporting noble soil to the Viau sector would have produced just as much, for a total of 170 tonnes of GHGs.
That’s not all: we have to factor in the energy needed to extract and crush the noble soil at the quarry.
Better yet, the solidification technique saves 200 mm of material thickness. Traditionally, a metre of soil is excavated and then 800 mm of granular foundation is poured in, then the paving is carried out. By using the soil solidification technique through encapsulation, we don’t need to deposit 300 mm of solidified soil on the bottom, then 300 mm of foundation and top it all with paving.
Claude Beaubien, chief engineer, Infrastructure
Management. His team is a pioneer in the field.
Through this soil recovery and reuse project, the Port of Montreal is emerging as a pioneer: “This is just the second project of its kind in Quebec,” proudly stated Hugo Brassard, engineer at the Port of Montreal. The first was a pilot project conducted by the Quebec ministère du Développement durable, de l’Environnement, de la Faune et des Parcs du Québec (MDDEFP) on the land of an old galvanizing plant, to test the process.”
At the Port de Montréal, the project is part of the redevelopment plan for the Viau and Maisonneuve sectors to increase their container handling capacity. This work called for major investment, to which the federal government has contributed $15 million.