Dutch A4all Tramway EPS Embankment with Vertical Sides

New section of the motorway A4 in the urban area between Vlaardingen and Schiedam is constructed in a concrete tunnel realized on ground level and covered by soil for a minimal environment impact. This new A4 route crossed the existing tram tracks. The construction of the tunnel with belonging embankments resulted in a 6 m high position of the tramway overpass. Despite low bearing capacity of the local subsoil the strict settlement requirements were valid for the ≥180 m long embankments on both sides of the motorway tunnel. Additionally complicating aspect was the realization period of only twelve weeks. Also the inconvenience to local residents living in surrounding large apartment buildings had to be minimized. Therefore, almost entire embankment length has been realized using 22,000 m³ EPS geofoam blocks. Applied embankment cross section design with vertical sides without slopes made it possible to realise the cross sections in two phases. Firstly, the northern cross section half with a pavement structure at the top was completed. Otherwise the original tram line could not stay in service during time of construction and the deadline of twelve weeks could not be met. These twelve weeks were necessary to complete the embankment cross section with the southern half. The new tram tracks are assembled at the top of it. The applied design approach for a phased realization of the 20 m wide lightweight embankment cross section is unique for Dutch engineering practice.