EFFECT OF GEOGRID ORIENTATION FOR CONE PENETRATION RESISTANCE OF SAND USING NUMERICAL AND ANALYTICAL MODELLING

Abstract

In the present study, the problem of low resistance offered by the soil to penetration is solved to a great extent by reinforcing the soil withgeogrid. The results of the cone resistance vs penetration were observed to be dependent on the orientation of geogrids. The geogrids were reinforced at bottom of the container and depth of 5.5cm and 11cm in the horizontal direction. The cone resistance is determined atthe densities of 1.54 g/cc, 1.59 g/cc, and 1.65 g/cc respectively of soil. Nineexperimental data set valuesled us to the conclusion that the best cone resistance was offered at the maximum dry density and the water content being at optimum moisture content.When geogrids being reinforced at bottom of the container and a depth 11 cm of the soil layer, the cone resistance was observed to be 3.6 times higher than that obtained in the case when the soil was not reinforced.1.2 times higher cone resistance was observed than that when the geogrids are reinforced in three layers of the soil. The analytical results were analyzed with a numerical modeling program. The results were validated by performing numerical modeling against the field results. A dimensionless cone penetration resistance factor(DCPRF) led us to the validation of the numerical model. DCPRF relates the ratio of cone penetration resistance obtained in the analytical modeling with the numerical modeling. DCPRF converges to unity as the value of the factored load is increased. DCPRF in sand reinforced with geogrid has more importance than cone penetration alone observed in the literature.