Wayne Douglas (co-author)
GeoMontreal (October 2013)
Increased activity in northern Canada is putting pressure on the existing infrastructure in oil and gas, mining, forestry public highways and other industries. This is happening at the same time as the demand for materials and manpower grows.
This Increased pressure has led owners, engineers and contractors to utilize more innovative solutions in both design and construction. An example of the need to meet economic and time restraints is one of Suncor Energy Inc. (Suncor) projects in Northern Alberta. The Suncor site is an in-situ oil recovery project located on leases known as "Firebag". The Steam Assisted Gravity Drainage (SAGD) technology uses underground wells to inject steam into the oil sands deposits and collect the bitumen released by the heat. The challenge is that much of the development is founded on peat, the removal of which would present considerable environmental and cost impact. The use of modern investigative methods and new geogrid products (TriAx®) enabled design and construction to proceed expeditiously. The use of LIDAR (light detection and ranging) was combined with Ground Penetrating Radar (GPR) to determine the extent and depth of the peat deposit at each of the multiple sites as well as the connecting road system.
This information was then supplemented with soils information obtained from boreholes and design was carried out using geogrid reinforced embankments and reinforced granular surfacing. The design approach was to make the structures as light and strong as practical in order to reduce the quantity of embankment fill and gravel required for the project. This lighter, stronger structure was not only more economic but was also safer due the reduction of the applied dead load. The reduced cross section also resulted in a reduction of the settlement that otherwise would have occurred. A number of these sites have been completed to date and more are underway. Those sites that are now in service are performing well and observations obtained from these sites are being used to fine tune the design and construction of future sites.