Numerical prediction and back-calculation of time-dependent behaviour of Ballina test embankment

The paper describes the Class A prediction and Class C back-calculations of the Ballina test embankment using the finite element program Plaxis and the Soft Soil Creep Model (SSCM). The prediction underestimated the measured settlement 3 years after construction by about 20%. This was mainly due to too high stiffness in the transition zone beneath the clay and that SSCM underestimated the shear deformation of the clay. Furthermore, the horizontal permeability of the clay was overestimated. In the back-calculation, it was possible to obtain a excellent match with the measured settlements by reasonable modifications of the input parameters.