Year
2013
Client
United Rentals,
Canada
Project Overview
A steep hill located at the residential intersection of Cliff Street and 23rd Avenue SW in Calgary suffered from repeated sloughing at the toe – the point where the roadway meets the existing ground line – creating drainage concerns and safety hazards for nearby residents. The existing native clay subgrade con¬tributed to the slope failure; chronic surface erosion, by precipitation and natural runoff, further weakened the area. The objective was to find a reliable earth-retention and erosion-control solution that would mitigate the immediate problem and require minimal repair or maintenance going forward. In September 2013, Paradox Access Solutions supplied Tough Cell® Geocells to Green Patch Inc. for roadside slope remediation work. The slope was graded and terraced prior to the installation of Tough Cell® and later mulched to stimulate natural growth remediation of the area. The project: •Eliminated environmental risk by improving slope stability •Enhanced the overall sustainability and safety of the adjacent neighborhoods •Delivered cost savings and rapid installation with minimal traffic imped¬iment
Year
2013
Client
United Rentals,
Canada
Project Overview
A steep hill located at the residential intersection of Cliff Street and 23rd Avenue SW in Calgary suffered from repeated sloughing at the toe – the point where the roadway meets the existing ground line – creating drainage concerns and safety hazards for nearby residents. The existing native clay subgrade con¬tributed to the slope failure; chronic surface erosion, by precipitation and natural runoff, further weakened the area. The objective was to find a reliable earth-retention and erosion-control solution that would mitigate the immediate problem and require minimal repair or maintenance going forward. In September 2013, Paradox Access Solutions supplied Tough Cell® Geocells to Green Patch Inc. for roadside slope remediation work. The slope was graded and terraced prior to the installation of Tough Cell® and later mulched to stimulate natural growth remediation of the area. The project: •Eliminated environmental risk by improving slope stability •Enhanced the overall sustainability and safety of the adjacent neighborhoods •Delivered cost savings and rapid installation with minimal traffic imped¬iment
Challenges
Paradox’s patented Tough Cell solution was the most suitable technology for reinforcing the ground on this site. Tough Cell met all requirements specified by The City of Calgary, including (but not limited to):
Unstable Terrain
Transportation Costs
The installation and backfill was completed using limited equipment. Mulch and hydro seeding were done post-install by the City.
Earth Retention & Erosion Control
Stabilizing a steep slope with a poor natural clay subgrade in a residential area while preventing erosion and drainage issues.
Our Approach
The City of Calgary (Project Owner) and Golder Associates (Consulting Engineers) opted to use Tough Cell® Geocells to assist in stabilizing the subject slope. A single layer of 150 mm height Type C Tough Cell® Geocells was installed over the prepared, graded, and terraced slope. The treated slope area was approximately 400 m2, with a length of 23 m and width varying from 8 to 23 m. The geocells were filled with 10cm of soil, and the final reinforced slope mulched and later seeded for additional protection against future erosion. The Tough Cell installation work was supervised by representatives of the City of Calgary and Golder Associates during construction.
What is Tough Cell?
•A polymeric alloy constructed from Neoloy that is superior to other geotechnical engineering solutions. Its supreme tensile strength and unique honeycomb shape reinforce and provide load support for heavy-duty applications of all kinds. Paradox Access Solutions is Canada’s only licensed provider of this durable and multifunctional product. •Typically used for road and yard surfaces, Tough Cell also provides soil stability and erosion prevention when used for slopes and inclines to need reinforcement.
Advantages
•Reduces the settlement of ballast ma¬terials and fouling by subgrade attrition •Is particularly effective for building over poor soil subgrades •Can be installed year-round in a timely manner, regardless of the season or weather •Supporting multi-directional confinement, Tough Cell enlarges the influence zone to 50-200mm, above and below cell height. Tough Cell can cover load support reinforcement and areas where water and drainage capabilities need to be considered
Benefits
•Supports a natural vegetation growth environment through erosion control and slope protection, in comparison to other geotechnical solutions. •Easily installed with minimal disruption to the natural environment. •75 year guarantee
The road utilized two layers of Tough Cell®, while the pad utilized three layers of Cells. Both were filled with local materials while aggregates were supplied by local quarries, within ±30km radius.
The road was 4.3 kms in total and finished with a width of 8 meters The Pad was 210m x 195m (40,950m2)
Aggregate materials required are significantly less than conventional methods, due to eliminated requirement for excavation and replacement of organic materials. This resulted in a huge carbon savings usually incurred through expensive excavation & hauling of aggregate material.
Results
With proximity to residences and natural areas, the installation was per¬formed with minimal disturbance and backfilled with a compact doz¬er-front track loader. Mulch applied post-install and subsequent hydro-seed¬ing restored the slope to its green glory with robust flora regrowth and zero slope structure failure one-year post-install.
The City ben¬efited from cost savings and rapid installation with minimal traffic imped¬iment in addition to a maintenance-free solution with an expected design life of >75 years. The area boasts an aesthetically pleasing natural appearance, with no negative environmental impact.
