Performance of Embankment Stabilized with Vertical Drains on Soft Clay

Abstract

This study describes the performance of a full‐scale embankment raised on a soft marine clay, stabilized with vertical band drains in Malaysia. The finite element code CRISP, which is based on critical‐state soil mechanics, has been employed to investigate the performance of the embankment and the underlying soft clay. Predictions of the excess pore pressures and both vertical and lateral displacements are made and compared with field observations. The limited use of closed‐form solutions for the prediction of settlements at the line of symmetry of the embankment is also discussed. The effectiveness of the prefabricated drains has been evaluated according to the rate of excess‐pore‐pressure dissipation at the soil‐drain interface. The numerical approach is based on a coupled consolidation analysis rather than on a conventional, purely undrained analysis. The numerical analysis reveals that for efficient vertical drains, the influence of smear and well resistance can be ignored. While the assumption of perfect drains may be acceptable in the long term, the short‐term settlements are governed by the drain efficiency.