By Nilex – For the Lac La Biche community, located 220 km north of Edmonton, Alberta, the surge in oil sands development has been accompanied by a more disciplined approach to planning and cost controls. A major part of those cost controls is in the design and execution of modular construction. When Lac La Biche Transport required a cost-effective solution for a low maintenance, unpaved yard, Nilex presented a geosynthetic solution that would support a long service life and perform under the heavy loads of modular assembly.
MODULAR ASSEMBLY YARD CONSTRUCTION
Based upon a SpectraPave4-PRO Software analysis of the site’s support and loading conditions and serviceability constraints, Nilex recommended the client use TriAx® TX160 geogrid and Nilex 4551 nonwoven geotextile. The software analysis demonstrated that using TriAx TX160 would reduce the granular thickness required by more than 50%, presenting advantages of faster construction, decreased aggregate costs, and improved sustainability in the engineered works.
The unique triangular aperture of the specified geogrid, combined with the material’s increased rib thickness and junction efficiency, greatly improves aggregate interlock and confinement. This leads to optimal structural performance of the mechanically stabilized layer.
During installation, the nonwoven geotextile was placed over the prepared subgrade, providing a layer of separation and protection. The geogrid reinforcement was installed next, followed by 300 mm of D2-20 mm aggregate.
The exceptional robustness and strength of the geosynthetics reduced the required granular fill thickness so significantly that more than 100,000 tonnes of fill were eliminated. The time to construct the yard was cut in half, with so much less aggregate needing to be hauled, placed, and compacted.
COST-EFFECTIVE SOLUTIONS
The client required 48,000 m3 less aggregate versus a conventional design, because of the TriAx® reinforcement solution. For Lac La Biche, the ready-to-execute design offered a savings of more than $3,000,000.*
Also, the approach decreased the carbon footprint by 1,700 tCO2.
Geosynthetics provided a strong, long-lasting, low maintenance solution with clear technical, environmental, and economic advantages.
For more civil and environmental engineering project stories, and for access to numerous resources and contacts in working with geosynthetics, visit www.nilex.com.
* Estimated using Nilex’s Innovation Calculator. Takes into account materials, labor, and placement costs.
