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First step to model the installation effect of geosynthetic encased sand columns on existing columns

Installation effect of encased sand columns on virgin soil and surrounding columns is an important field in geotechnical research domain. Numerical simulations of a step of the installation pro-cess of geosynthetic encased sand columns (GEC) in soft soils in the Coupled Eulerian Lagrangian (CEL) framework is performed. Installation of 400 mm diameter geosynthetic encased stone columns is simulat-ed. A 400 mm internal diameter steel probe filled with granular material and surrounded by geosynthetic is modelled to execute the installation process. The soft soil and granular material in the column was modelled by the visco hypoplastic model and hypoplastic model respectively. The geosynthetic is mod-elled as an elastic material with an out of plane tensile strength. The real life installation of encased sand columns is performed in steps over the entire depth of column however in the work, a single installation step was modelled due to computational constraints. An already wished in place full depth column was modelled at the start of the simulation followed by the installation of an adjacent encased sand column. The installation effect of encased sand column on the adjacent column in terms of the developed stress state and deformations in and around the already existing column is studied. The effect of nature of soft soil and spacing between columns is analyzed. The simulation of the installation process shows that de-formations in the already existing sand column was a function of the column spacing and soft soil strength.