Project Summary
Previously, a vegetated wrap wall was installed during the initial slope construction to help establish vegetation and limit erosion. Unfortunately, the south-facing wall was not performing to standard, and it struggled to establish vegetation and had ongoing erosion issues.
Project Scope and Challenges
The surrounding infrastructure, including roads and ponds, was complete and could not be altered. The slope is south-facing and 160m long with a 1:1 slope with varying heights (from 12.8m to 4.4m). One of the main concerns was the proximity to the road and the block wall, located less than 2m from the top of the slope, creating a challenge for access and anchoring.
Solution
Layfield proposed a Presto Geosystems GEOWEB® slope protection system. The customer agreed to move forward with GEOWEB® and thought it would also be a good option in allowing them to create a design or picture on the slope using two colors of stone. Many underpasses around Calgary have mountainscape designs using concrete; this design would have a similar
appearance.
Presto Geosystems and Layfield provided a design and plan for the slope. Due to the road’s proximity to the top of the slope, innovative anchors were needed. Based on pullout force calculations, North American Green Falcon Anchors™ were selected to secure and support soils.
Installation
The customer’s team had never used GEOWEB® before and required extra help from Layfield staff to ensure proper installation. However, it was a quick and efficient process once installation had started. The first step was to remove the vegetation and then cover it with LP8. Then, the Falcon Anchors™ were driven into the ground, and pullout force tests were completed on every anchor used. GEOWEB® was deployed with tendons that were pre-measured and installed. Finally, the stone was carefully placed into the cells to form the mountainscape image.
Results
The solution chosen provided cost savings and the ability to protect from erosion without the need for vegetation. The project was completed on time and budget, while the final placement of the aggregate on the wall was aesthetically pleasing and appreciated by the surrounding homes and parks.
Features & benefits
GEOWEB® geocells are an economical solution for erosion control. The 3-dimensional GEOWEB® structure holds the upper soil layer on the slope and prevents washout from water action or other erosive forces. Falcon Anchors™ are designed to firmly secure and support soils deep into the soil strata.
