RS580i - CNRL Kirby
Location: 40KM south of Fort McMurray AB
Timeframe: Pending July 2103
Scope of Work: Design and Supply Geosynthetic Reinforcement
Project Partners: Jacobs Engineering – Graham Chambers – Senior Civil Engineer Tencate / Mirafi – Andy Lister, Bruce Lacina, PE and Rene Laprade CNRL – Lee Cottreau - Construction Manager
Background Information and Challenge
Jacobs on behalf of the owner of the project asked Layfield to review provide a recommendation for the granular cross section within the new CNRL Kirby location. What we had been given was detailed analysis on the in situ soils the planned traffic patterns and frequency of both the plant site and the reinforced roads structure throughout the plant site. We needed to build a robust design to withstand construction traffic and function throughout the 25 year design life of the plant location. They wanted us to make recommendation using new generation Geosynthetic materials to build a robust structure and reduce maintenance and overall required granular fill. In this project location granular material must be imported, crushed on site and deployed; based on info from the owner we used $100.00 / m3 as a cost for deployed granular material. The geotechnical engineer had originally recommended the following cross section
Native clays – scarified and compacted to 98% SPMDD along with removal of any less than suitable material – LP315 – slit woven geotextiles was to be deployed and then a 450mm lift of 80mm minus followed by a 50mm layer of wear course 25mm crush. This cross section was to be applied to the entire plant site area ( other than where building sat) this was an area approximately 228,000 m2 - in addition they recommended that an additional 150mm of 50mm minus be used to reinforce the plant road cross sections.
Working through our design and engineering partners at Tencate/Mirafi we applied a detailed ASHTO pavement design using the NEW Giroud-Han methodology for creating a reinforced cross section using geosynthetics. Our accepted design used the latest high Strength Mirafi product RS380i - the newest member of the RS series of materials.
The revised cross section created a design equivalent to a much more robust cross section that the original recommendation 47% thicker as a fact – By running the full design calculation based on the data that was given to us we determined that the original design we had been asked to review and revised would have failed as it didn’t provide enough structure for the anticipated loads.
For the plant site we recommended the following:
Native clays – scarified and compacted to 98% SPMDD along with the removal of any less than suitable material. RS380i High Strength Reinforcement Geotextile with a 300mm compacted layer of 50mm minus stone. This cross section was to be applied to the entire plant site which created a projected savings of 40% of the overall granular compared to the original design. To reinforce the road sections we recommended an additional 150mm of 50mm crushed stone and this actually represented a 31% reduction in the cross section for the roads and was designed to be a much more robust cross section that the original design.
Through the application of the revised design we have created a granular savings for the entire plant site of 45,600 m3. If you calculate the savings using the $100 / m3 value of stone that creates a savings of $4.56 million dollars. Take into account the added benefit of fuel and environmental impact reduction related to NOT having to haul and deploy over 1800 truckloads of stone to the location made this an easy choice for the owner.
Project is currently scheduled for construction in July of 2013 – updated pictures of the installation and fabrication of the RS380i sewn textiles from our fabrication plant in EDM will be posted as they come available.