Jet-grout column-reinforced soft soils incorporating multilayer geosynthetic-reinforced platforms

Geosynthetic-reinforced load transfer platforms are commonly used in constructions over column-reinforced soft soils and correspond to modifications of conventional granular load transfer platforms that utilise only the arching effect of the granular soil to transfer the loads onto the columns. Both a single geosynthetic layer and several geosynthetic layers can be used to reinforce the granular soil of a platform. Most of the studies published in the literature address the use of single geosynthetic-reinforced platforms, while there is a lack of studies on multilayer geosynthetic-reinforced platforms. In the present study, to help overcome that lack, a jet-grout column-reinforced soft soil foundation with a platform that incorporates five geosynthetic layers is analysed. A parametric study is also performed in order to analyse the influence of four key factors. A numerical code based on the finite element method is used, incorporating a fully coupled analysis and soil constitutive relations simulated by the p-q-θ critical state model. The study mainly shows that a larger number of geosynthetic layers within the platform brings about better geotechnical behaviour of the column-reinforced soft soil foundation in terms of the settlement and the load transfer onto the columns.