Back analysis of the Cumbalum Trial Embankment

A trial embankment has been constructed on a deep soft clay deposit near Ballina. The monitoring data has been back analysed using one-dimensional consolidation theory. The results of the back analysis indicate that a more highly compressible layer exists beneath the embankment than was identified during site investigations. It is inferred that this layer might comprise a structured soil. Implications for design of embankments on such soils are discussed.