Segmental retaining walls using lime stabilised soils in the new venice bypass (Italy)
The choice of reinforced segmental retaining walls with PVA geogrids proved to be a valid alternative to standard concrete retaining walls, both from the technical and aesthetic points of view. Due to the flexibility of the system it has been possible to achieve a much better behaviour than rigid concrete walls founded on piles in terms of elasticity and in terms of possibility of redistributing absolute and differential settlements.
Thanks to their good chemical resistance in alkaline environments, it is possible to use PVA geogrids as reinforcing elements also in embankments where lime stabilized soil is used as fill material (pH > 12), thus opening a new alternative where the use of other types of reinforcements is not possible.
The geogrid reinforced segmental retaining walls technique gave the possibility of building the whole embankment together with the wall, while in case of concrete structures the contractor would have to wait for the curing of the concrete before laying and compaction of the embankment fill.
Furthermore all the aesthetic prescriptions have been fulfilled, giving to the embankment an environmentally friendly look; the concrete blocks were also used as a facing for the bridge abutments, thus giving a harmonized look to the whole structure.
The first of the two embankments approaching the bridge have been completed last winter (4.000 square meters of facing), while the other one in currently in the construction stage winter (4.000 square meters of facing).