Finite element analysis of soil containing vertical drains : Russell, D Ground EngngV25, N6, Aug 1992, P20–24

Abstract

The construction of embankments over soft, compressible soils can cause considerable problems to the geotechnical engineer. Expedients such as reinforcement, vertical drains or stage construction are often necessary to achieve an efficient, economical design. The analysis of such embankments becomes complex and requires the use of a numerical technique such as the finite element method. Although the use of vertical drains has become widespread in embankment construction the finite element analysis of such problems has only occasionally been reported. The reason for this may be the difficulty in equating the plane strain embankment analysis with the essentially axisymmetric consolidation behaviour of the soil surrounding a single vertical drain. In this paper a method for the plane strain finite element consolidation analysis of soil improved by vertical drains is presented. The consolidation of axisxmmetric and plane strain unit cells, representing the soil around a single drain, are compared for a normally consolidated clay deposit. The clay formed part of the subsoil at a well documented construction project which has been analysed in full plane strain. Results from the finite element prediction are compared with published observed behaviour. All the finite element analyses were performed using a modified version of the program CRISP. (A)