Aesthetic and affordable ground reinforcement

The Oosterweel connection is the project to close the Antwerp Ring Road (R1) along its northern side. In the Flemish government's current plan (BAM route), the Expressway (E34) is led under the Scheldt via a tunnel (the Oosterweel Tunnel) near the Blokkersdijk on the Left Bank and connected to the R1 at Merksem and Deurne via additional tunnels under the Albert Canal. Initially, study firm BAM proposed a double-deck bridge (the Lange Wapper Bridge) for this last section, but this was replaced by a tunnel in more recent plans.

Lack of space is a challenge when constructing new ramps for existing roads. Slopes that retain their natural slope take up too much space. After all, next to the new structure is another road, a bike path, a waterway or standing buildings. Slopes should therefore be built as steeply as possible. For this, the principle of reinforced earth offers a solution. In the backfill soil, layers of plastic or a steel mesh with high strength and small deformation are applied. Thanks to their friction with the layers of backfill soil, the embankment is stable.

Building an aesthetic and affordable ground reinforcement

If the designer wants to give the slope a beautiful and environmentally friendly aspect, it should be possible to grow vegetation on the often steep slope. A steel mesh: strong yet permeable.

In this case, the most sustainable and at the same time most environmentally friendly solution is to ensure the stability of the slope by incorporating a steel mesh. Such a net not only reinforces the ground, it also allows you to create a beautiful, green day side with vegetation or, of course, you can opt for a finish with broken stones. 

Geosynthetics, including geogrids, are well suited for the realization of steep slopes with reinforced earth. The calculation methods to calculate strength as a function of long-duration loading are similar for most products. Most often the Bishop method with slip circles and shear stresses is used. Terramesh is a total system that not only reinforces the soil horizontally, but also allows execution without formwork. 

"The contractor can work exclusively from the side of the recharge. Given the slope of the embankments (70° and more) and the height of up to 17 meters, this is an important advantage," explains Steven De Maesschalck of Texion. "The Terramesh elements are delivered as units, including reinforcement, day side, erosion-resistant geotextile and brackets that secure the 70° angle with the horizontal."

This overall system results in great installation efficiency. Terramesh allows you to realize whimsical geometric shapes, which was needed near the structures and for the bridge abutments. On the Oosterweel link, both Green Terramesh (GTM), supplemented with soil, and Mineral Terramesh (MTM) and Terramesh System (TMS), supplemented with stones, were used. Terramesh has the British Board of Agrément (BBA) certification, offering a guaranteed service life of more than 120 years.