In a rapidly changing world, maintaining and improving our transportation infrastructure’s resilience and sustainability has become a critical concern for civil engineers. Climate change and increasing frequency of natural disasters present an ongoing challenge to the durability of our infrastructure. In the context of road and bridge embankments, protecting these structures can be of paramount significance to the safety and welfare of the public. These structures are often subjected to fluctuating environmental conditions, heavy traffic loads, and must be able to withstand major storm events to protect embankment materials from soil washouts and the long term damaging effects of erosion. So how can civil engineers meet these growing demands without compromising sustainability or longevity? Increasingly, engineers are turning to geosynthetic solutions, such as the GEOWEB® Soil Stabilization System—a low-maintenance and eco-friendly solution for long-term protection of road and bridge embankments.

In many cases, the GEOWEB Geocells offer a flexible, durable, and environmentally responsible alternative to traditional construction materials that can accommodate a wide range of infill materials, including soil, aggregate, or concrete, to establish hard or soft armor, as necessary, for protection as well as aesthetics. As we explore the capabilities of the GEOWEB Geocells, we will find that this solution not only addresses some of today’s most pressing infrastructure challenges but also paves the way toward a more resilient and sustainable future.

Improving Bridge Resilience with the GEOWEB Geocells at the I-90 Mississippi River Bridge

Bridge stability relies heavily on the long-term integrity of its abutments. Any vulnerability or weakness in these components can lead to structural failure with a potentially disastrous outcome. Therefore, prioritizing the design and construction of resilient abutments is crucial to ensure the stability and longevity of bridges.

In 2013, the I-90 Mississippi River Bridge, or the Dresbach Bridge, underwent a significant reconstruction project led by SRF Consultants. The aim was to replace the old bridge on the Wisconsin/Minnesota border and improve the interchange between Highway 61/14 and I-90 to enhance traffic safety and provide better access for motorists.

The GEOWEB System played a crucial role in two different applications. The GEOWEB sections (4-inch-depth, mid-sized cell) were utilized on slopes directly beneath the bridges and around structural supports, ranging from 2H:1V to 1.5H:1V, with heights up to 45 feet. These sections, filled with aggregate, were custom-produced in a tan color selected to blend in with the local aggregate color, improving visual aesthetics. Standard black GEOWEB sections  (6-inch-depth, mid-sized cell) were used around the bridge abutments on slopes varying from 2.5H:1V to 3.5H:1V, reaching heights of up to 48 feet. These sections were filled with topsoil and covered with an erosion control blanket to support vegetation.

To secure the GEOWEB sections to the slopes, 18″ ATRA® Anchors were employed, with the anchor pattern adjusted to suit different slope characteristics, section depth, and infill material. The Presto Geosystems engineering team provided calculations and recommendations for anchor spacing in each of the 11 application areas.

The implementation of the GEOWEB Soil Stabilization System in the Dresbach Bridge project was completed in the fall of 2016. This versatile system continues to provide robust slope protection, offering benefits for both aesthetics and long term project resilience. The Dresbach Bridge project serves as a testament to the versatility and effectiveness of the GEOWEB System in achieving slope stabilization and erosion control objectives around a vital piece of U.S. transportation infrastructure.

Fortifying the Roadway Embankment along River Road in Lewiston, Maine

Roadway embankments are another critical component of transportation infrastructure that face similar challenges. Erosion, washouts, and landslides can all lead to road failure, posing significant safety risks and disruptive repair costs. To protect against these risks, the GEOWEB Soil Stabilization System adds a valuable layer of protection. The three-dimensional honeycomb-like structure confines infill materials and protects slopes from sheet flow runoff, washouts, and shallow translational failures that can occur during and following major storm events.

River Road in Lewiston, Maine, faced a similar challenge due to its steep 1:1 slope and heavy traffic, including constant truck flow. To ensure the long-term safety and integrity of the road, the River Road Reconstruction project was initiated, which included pavement reconstruction, shoulder widening, and construction of a stabilized vegetated slope, among other upgrades.

One significant hurdle was constructing a 45-degree vegetated slope, with the risk of erosion heightened during spring seasons due to rainfall and snowmelt. To maintain the slope’s stability and the road’s integrity, the GEOWEB Vegetated Slope Protection System was chosen for soil stabilization and erosion control.

The system’s installation process utilized geogrid lifts for enhanced slope stabilization. The 3D cellular GEOWEB system, combined with a tendon system, held the topsoil in place on the steep slope, enabling sustainable vegetation growth and mitigating severe erosion risk.

The GEOWEB system was filled with rocks at the slope’s toe for a strong foundation, with larger rocks on top for added support. Moving upwards, cells were filled with topsoil and covered with a turf reinforcement mat to promote grass growth, demonstrating the pivotal role of the GEOWEB geocells in providing stability, soil confinement, and vegetation support.

A Step Forward in Sustainable Infrastructure

In the face of modern infrastructure challenges, civil engineers need solutions that are not only resilient but also sustainable. GEOWEB Geocells provide a dynamic response to these demands. They offer significant benefits in terms of durability, adaptability, and environmental consciousness, making them an optimal choice for modern bridge and roadway embankment projects.