Stability and the time required for consolidation are two key considerations with respect to the construction of embankments over soft clay deposits. Several techniques have been developed to improve embankment stability and accelerate consolidation. These techniques include the use of geosynthetic basal reinforcement to reduce the outward shear force on the foundation soil (e.g. Rowe, 1984; Fowler and Koerner, 1987; Jewell, 1987; Rowe and Soderman, 1987; Rowe and Li, 1999; Bergado et al., 2002; Shen et al., 2005; Rowe and Taechakumthorn, 2007a; Kelln et al., 2007 and many others) and the use of prefabricated vertical drains (PVDs) to accelerate pore pressure dissipation in the clay (e.g. Crawford et al., 1992; Bergado et al., 1997; Chai and Miura, 1999; Li and Rowe, 1999; Indraratna and Redana, 2000; Bo, 2004; Chai et al., 2004; Rujikiatkamjorn et al., 2007 amongst many). For the case of a conventional soft clay deposit, the combined use of geosynthetic reinforcement with PVDs has been studied by several researchers and been shown to allow the rapid construction of higher embankments than would have
been possible with the use of either method alone (Li and Rowe, 2001).