Reinforced Embankments on Soft Deposits: Behaviour, Analysis and Design

Abstract

This paper reviews the key mechanisms on how basal reinforcement improves embankment behaviour through an examination of cases where embankments were constructed on soft organic clay and peat. The embankment responses from undrained and partially-drained simulations are compared to highlight the effect of consolidation during the construction. The benefits from the combined use of basal reinforcement and PVDs are presented. This paper also provides an overview of a design approach for embankments on soft ground taking account the interaction between basal reinforcement and PVDs as well as explores the effect the time-dependent behaviour of geosynthetics and rate-sensitive soils on the long-term performances of reinforced embankment under working condition. The limitations of the current design method are discussed. Finally a case study involving a reinforced embankment constructed over soft sensitive clay with a weathered crust is presented to illustrate the effect a stiff crust and soil structure can have on the effectiveness of the basal reinforcement used for this particular case.