Critical length of encased stone columns

Encased stone columns are vertical inclusions in soft soils formed by gravel wrapped usually with a geotextile. Their critical length is the one where further lengthening of column provides negligible improvement and it therefore not effective to build longer than it. This paper aims obtain common values using simplified two-dimensional axisymmetric full three-dimensional finite element analyses. A uniform soil layer linear elastic perfectly plastic behaviour considered for sake simplicity. For studied cases, around 1.3–2.5 times footing diameter encased columns, slightly lower ordinary namely 1.1–1.9. The encasement found be length. value related extent deformation that may used decide design phase without need parametric As first approximation, general 2 2.5 respectively. • Parametric numerical analyses performed study columns. Critical should expressed as function width. zone deformations present. geosynthetic larger non-encased ones.