Analysis of impacting factors for soil-cement column combined high strength geogrid

Abstract

Soil-cement column combined with geogrid on top or Geogrid Reinforced Pile Supported (GRPS), is used to construct structures on soft ground. Because of its high tensile capacity, the geogrid is spread on the top of the soil-cement column to form a soft transmission layer, increasing the capacity transferred to the columns, reducing a part of the load transmitted to the soft soil between the columns. The numerical analysis results of the GRPS with a high strength geogrid showed four major factors affecting transmission the efficacy of the column (Ef) and the tensile force of the geogrid including effective vertical load (v’); the ratio of the distance between the columns and the column’s diameter (s/D); the ratio of the elastic modulus of the soil-cement column to the deformation modulus of soil (Ec/Es); the tensile stiffness of the geogrid (J). The efficacy of the column (Ef) increases rapidly with an increase in effective vertical load (v’) from 0.23 to 0.44. In contrast, the transmission efficiency (Ef) decreases from 0.60 to 0.37 when s/D increased. When the ratio Ec/Es > 150 and J > 8000 kN/m, the tensile force of the geogrid tends not to change much.