The Sierra Slope Retention System offers a greener, more cost-effective solution than concrete panel walls.

The Port Mann/Highway 1 improvement is a $2.5 billion project which included the construction of the new Port Mann Bridge, widening of Highway 1, replacing nine highway interchanges and improving safety. The project spanned a distance of approximately 37 kilometres from Vancouver to Langley, British Columbia.

At 65 metres wide, the new Port Mann Bridge has officially been recognized by the Guinness Book of World Records as the widest bridge in the world. The 10-lane bridge is also the second longest cable-supported bridge in North America.


Lower Mainland, British Columbia


Sierra Slope®
Silt Fence
Biaxial (BX) Geogrids
NuDrain™ Sheet Drains

Project Partners

  • Owner: BC Ministry of Transportation
  • Consultant: MEG Consulting & Thurber Engineering
  • Contractor: Kiewit/Flatiron General Partnership
  • Completion Date: December 2013


The Mechanically Stablized Earth (MSE) aspects of the project were originally exclusively specified as concrete panel walls with steel reinforcement. In addition, with the widening of the highway, the walls were being built on soft soils within space constraints and the contractor needed to replace lost green space.


Nilex approached Kiewit/Flatiron and the BC Ministry of Transportation (MoT) with an alternative solution consisting of Sierra Slope and SierraScape. Sierra Slope has a naturally vegetated face and would maximize the use of the restricted construction space. It is lower in cost than concrete retaining walls and would effectively replace the specified panel walls. The flexible nature of Sierra Scape makes it well suited for applications prone to differential settlement.

In addition to providing the MSE systems, Nilex provided RhinoskinTM to protect the Expanded Polystyrene (EPS) lightweight fill, NuDrainTM WD15 to assist with drainage of the bridge abutments, silt fence and erosion control products to prevent sediment contamination of local water courses, Tensar Biaxial Geogrids for subgrade and base reinforcement, and Tensar Uniaxial Geogrids cast into Lock-Block walls which separated east and west bound traffic lanes. All of Nilex’s solutions were on the MoT’s approved products list. Nilex also performed a FLAC analysis to detail how the system would react during an earthquake.


Approximately 40 MSE structures were installed over the duration of this four-year project. Each wall was installed by hand only requiring excavators and bobcats for back fill placement, and bulldozers and vibratory riding rollers for compaction. Nilex was on site at least once per week to provide installation guidance.


The SierraScape Retaining Wall System and the Sierra Slope Retention System provided a greener, more cost-effective solution than the originally specified concrete panel walls. Nilex’s recommended solution allowed the contractor to significantly reduce the equipment and time required for installation. The new Port Mann Bridge is projected to sustain Vancouver’s traffic growth over the next two decades.

In July 2014, the Port Mann/Highway 1 Improvement Project was the recipient of the Lieutenant Governor’s Award for Engineering Excellence in British Columbia. This award is presented annually by the Association of
Consulting Engineering Companies of British Columbia to recognize excellence in engineering in a number of disciplines. Nilex’s work was recognized along with the project’s other major partners.


Nilex is committed to unearthing better results. Whether it’s for a civil, resource or environmental project, we offer the latest engineered and technically superior materials and techniques to save our customers time and money, and minimize the need to move or remove earth, and reduce the need for granular materials.

With over 35 years experience, a long-standing commitment to the environment and highly qualified staff, Nilex delivers the products and technologies that give clients an economic advantage with environmental benefit.