Riverfront Retaining Wall

Geocell Retaining Wall for Riverfront Home in Virginia

Project Details

Sector:
Residential

Location:
Heathsville, VA

Partners:
Presto Geosystems

Key Products:
GEOWEB®

About the Project

Years of coastal erosion took a toll on this riverfront property in Virginia. The homeowners needed a solution that would save their home and protect the property from future storms. Although many homes in Northumberland County reinforce their properties with hard armor, these homeowners invested in a geocell retaining wall.

Discovery and Design

In May 2021, a homeowner sought the advice of Colonial Construction Materials to save his home from coastal erosion. He explained that a major hurricane damaged the property several years prior. Since then, wind and rain continued to erode the property.

Tommy Branin visited the site to inspect the damage and access the site conditions. He witnessed the severe erosion that the owner had described; the stairs and dock were falling into the river, vegetation was losing its grasp, the slope was sliding into the water and the property line was receding. 

Although many coastal property owners in the region protect their homes with hard armor, we did not recommend rip rap for this property. Rip rap would have been expensive to haul to the site and difficult to install. Additionally, the homeowner wanted a solution that would allow easy access to the river and blend seamlessly into the environment. Most importantly, they needed a structural support system that could withstand future storms.

The Solution: GEOWEB^® Geocell Retaining Wall

We recommended a retaining wall supported by Presto Geosystems’ GEOWEB^® GW30V. A geocell retaining wall is a green solution that provides structural support while conforming to the natural contours of the landscape. The GEOWEB^® wall is built into the slope and has open-celled terraces that are filled with soil and planted with vegetation. This system performs well even in soft soils which was a critical factor for this coastal project.

The green wall system resists degradation because GEOWEB^® and ATRA^® Keys are made from strong and flexible HDPE. The lightweight and flexible geocell panels are easier to install that an MSE block wall, especially on a waterfront project like this one.   

Presto Geosystems provided the plans for the project and Northumberland County provided evaluation, design and permitting for the waterfront retaining wall. 

Retaining Wall Construction

After the existing debris and structures were removed, the slope was graded and prepped for installation. After grading, a six-ounce nonwoven geotextile fabric was installed. The nonwoven geotextile fabric retains the soil while creating a separation and drainage layer between the existing soil and the backfill. HDPE Pipe was installed to improve drainage in the wall system.

The retaining wall was built with lifts of uniaxial geogrid, 6-inch GW30V geocell panels and backfill. Two types of uniaxial geogrid were used for tieback structural support. This project required two different uniaxial geogrids, ERS-3 and ERS-5, because of the size of the wall which is 37-feet tall and 50-feet wide.

The backfill was compacted on each layer and a small setback was made before starting the next lift. The GEOWEB^® geocell panels were secured with ATRA^® Keys. The cells were filled with soil that was recycled from nearby construction sites. The type of backfill for geocell systems varies by project but generally it should be freely draining and compactable. The recycled fill met those requirements and was a good source of organic matter which helps the green wall vegetation to thrive.

Construction completed in the of Fall 2021. The slope was seeded with Fall Contractor’s Mix Grass Seed which contained a blend of Fescue, Annual Rye and Winter Rye. This first seeding established vegetation before the Winter. In the Spring of 2022, the slope was seeded with Pennington Slope Master. Monkey Grass was added for aesthetics and perennial growth. 

The GEOWEB^® geocell retaining wall met the homeowners’ desire for a green solution that has structural support. Now they have regained their once eroded yard, restored the the natural aesthetics of the riverside and can once again use their dock.