Cement Stabilized MSE Walls Reinforced with Polyester Straps: the Importance of Aesthetics in Engineering
Location of work/project:
Belgium – Antwerp
The project comprises of 123m span bridge and MSE walls with walkways and bike paths. The retaining walls, with polymeric strips in cement stabilized backfill, were designed meeting challenging aesthetical requirements. The new bridge is a crucial infrastructure, relieving the traffic load and increasing the people quality of life.
The “Brug van den Azijn” (Bridge of Vinegar) project is located across the Albert Canal in the city of Antwerp. The project is part of the Flemish Waterways Authority plans toincrease the river transport capacity. The project included bus lanes in both directions, a one-way cycle lane, and a pedestrian path. The abutments were designed to support a 123 m span arch bridge, with a clearance of 9.1 m high, allowing the passage of ships with four layers of containers. The recycling of the onsite material was possible by soil stabilization due to the high percentage of fines.
Two 300 m long reinforced soil ramps up to 10.5 m high were designed by Maccaferri. The system chosen is called MacRes and it is comprised of concrete panels and ParaWeb polymeric strips. These strips are made of high tenacity polyester yarn encased in a polyethylene (LLDPE) sheath. The reinforcements are the key structural component of the MSE wall system and are mechanically connected to the facing panels through a specially designed connection. The architects of the project designed an articulated façade for the bridge structures. Therefore, walls and true abutments were designed with a 75° inclination. The top panels of the reinforced structure had to perfectly match the wall elevation: each top panel was specifically designed to meet the project geometry. The client requested 0.75 m high panels, therefore a horizontal fake joint was included in the panels formliner. The precise alignment of the panel joints was possible thanks to AutoCad modelling based upon precise topographic measurements. No corner elements were casted for this project. Panels were properly aligned to create a continuous wall facing, smoothly curving along its development. Cladding elements were manufactured to cover the concrete abutments and provide the same aesthetical finishing adopted for the wall structures.