Bearing Capacity Analysis of Granular Soil with Geogrid

Abstract

The construction of any structure in poor soil condition is a difficult task for a civil engineer. Structure on the ground with adequate bearing capacity is one of the essential requirements for the stability of a structure. The properties of weak soil can be improved by inclusion and confinement by reinforcement. It can overcome the inadequate bearing capacity and excessive settlement problems of shallow foundations due to soft soil conditions. In this research, the ultimate bearing capacity of geogrid reinforced soil was determined by using both experimental methods and numerical analysis. The effect of inclusion and confinement by geosynthetic material in the soil was investigated. The soil used in this study was dry sand obtained from the Godavari River near Nanded (Maharashtra). The biaxial geogrid was employed as a soil reinforcement material which was manufactured by Strata Geosystem Private Limited, Mumbai, India. The trial set-up comprises a reaction frame, a mild steel tank, a hydraulic cylinder, a power pack, an electrical panel, and a model footing. The experiments were conducted in a Mild Steel tank of 750mm x 750mm x 750mm. A plate vibrator was used to compact the soil, and the vertical load was applied using a hydraulic cylinder of 50 kN capacity. The experiments were carried on 208 sets of distinct tests by considering the five parameters: the effect of the topmost layer of geogrid, spacing between successive geogrids, number of geogrid layers, the width of geogrid, and the eccentric loading conditions. The ultimate bearing capacity of soil for various configurations of geogrid was determined by plotting the load settlement curves for each set of tests. The experimental test results were validated by using the finite element tool OPTUMG2. The research problem was modeled in OPTUMG2 for different variables discussed in this research. The software uses limit analysis to get the collapse multiplier, i.e., ultimate bearing capacity using the upper and lower bound theorem. newlineThis study shows that the eff