Earthworks for roadworks

Earthworks for roadworks mainly involve the preparation and, as appropriate, movement of soil and rock to allow for the safe and economical construction of road pavements on stable foundations (including on embankments) and in cuttings. Fundamental requirements of the completed earthworks are to provide a stable construction platform for the placement and compaction of the overlying pavement layers and to minimise any settlement of the superimposed pavement over its design life.

With respect to a cutting, an additional basic requirement is the stability of its side slopes. If side slopes fail within the design life of the earthworks, the result will be the deposition of debris at the toe of the cutting and/or the failure of material at the base of the cutting. This will likely interrupt the safe movement of traffic and cause damage to the road surface and to verge services (e.g. to drainage and communication cables). With respect to embankments, side slope failures can result in the undercutting of the pavement asset that the embankment supports. Additionally, the gradual settlement of an embankment over its design life, while not necessarily contributing to catastrophic failure, can result in unacceptable differential movement leading to serviceability failure and temporary loss of service.