EXPERIMENTAL STUDY OF SOFT SOIL REINFORCEMENT WITH GEOGRID ARTIFICIAL GRANULAR COLUMN

This research aims to investigate; strength characteristics of artificial granular material for soft soil cement stabilization, design parameters of artificial granular column elements encased geogrid, and bearing capacity of artificial granular column soft soil reinforcement models. Artificial granular material consisting of triangular prisms, cubes and hexagon prisms of the same volume, made from cement stabilized soft soil using the trial mix method to represent strength equivalent design criteria of road sub-base layer. Artificial granular column elements test and soft soil reinforcement models test with geogrid-made granular column systems were carried out in each shape variation. Based on design criteria CBR value=20% for road subbase layer, then cement stabilization is set at 12.5% which corresponded to the value of qu=400 kN/m2 with cement water ratio w/c of 1.9. Sub-grade modulus column elements in various granular forms E=1.58-2.67 kN/m2 with poisson  =0.29-0.33, granular hexagon prism shows higher capacity performance and design parameters. Soft soil reinforcement model with artificial granular columns-geogrid is significance improving bearing capacity of soft soil foundation systems with an increase ratio of 28.5-33; the granular hexagon prism shows capacity performance and design parameters higher than other granular types