Gault Clay embankment slopes on the A14 – Case studies of shallow and deep instability

Instability of the Highway embankment slopes constructed from plastic over-consolidated clay fill is known to have occurred in the past, and observations suggest that instability is currently occurring at a number of identified sites (e.g. Perry, 1989; Greenwood, 1985; Stokes et al., 2004), producing costly maintenance problems

In order to design or evaluate an effective remediation that can prevent such instability, the performance of the embankments, the factors controlling the development of slip surface and stability degradation need to be understood.