Combigrid® Geogrids from NAUE Geosynthetics were used to provide a stable sub-base, over poor soil conditions, for the construction of a 60,000m2 parking lot at Vancouver Airport’s new shopping mall.

Richmond’s new McArthurGlen Designer Outlet is located just three minutes from Vancouver International Airport and 30 minutes from downtown Vancouver via the Canada Line Skytrain system. Leading up to the opening of the new mall, and within an extremely compressed time line, there was a need to build a temporary parking lot which would occupy an area of approximately 60,000m2 and provide parking for around 2,000 cars.

On initial inspection, it was soon determined that the site’s soil structure was poor; with evidence of 5” deep footprints throughout. However, the area had not experienced any significant rainfall for a number of weeks and dry conditions would help make it easier to complete the project on time. Preliminary designs called for reclaimed concrete aggregate at a depth of 400mm but, with speed and time lines being critical, design engineers looked at alternative ways to achieve the required strength while speeding installation.

A geogrid solution was recommended using NAUE Combigrid® 30/30 Q1 GRK3 151. Combigrid® provides reinforcement, separation and filtration, all in a single product. For this reason, the primary application for Combigrid® is on weak sub-soils where it interacts with the aggregate course and increases the shear strength and load capacity of the platform, while reducing aggregate depth requirements. A further benefit of Combigrid® is that it is extremely quick and easy to install. At the site, vegetation was removed and the uneven surface levelled. Tests, using a single roll, were carried out to establish functionality and to determine what depth of aggregate would be required. The load resisting properties of Combigrid® allowed the aggregate layer for the project to be reduced from a thickness of 400mm down to 300mm. In total, 125 rolls of Combigrid® were successfully installed directly onto the levelled soil, using standard width 4.75m x100 metre long rolls, followed by the aggregate fill layer. Combigrid® met or exceeded requirements over the poor soils and the parking lot was satisfactorily completed, on time, over a six week period.

Project Name: Temporary Parking Lot, McArthurGlen Designer Outlet
Location: Vancouver Airport, Richmond BC, Canada
Date: June 2015
Designer/Consulant: MMM Group Limited
Contractor: Jacob Bros. Construction
Product: Combigrid® 30/30 Q1 GRK3 151