NUMERICAL MODELLING OF PRESTRESSED GEOSYNTHETIC REINFORCED SOIL

Abstract

Rapid industrialization and increase in population have resulted in scarcity of suitable ground conditions. It has driven the need of ground improvement by means of reinforcement with geosynthetics with minimum possible settlement and with maximum possible safety. Prestressing the geosynthetics offers a very quick, economical yet safe method of gaining the goal. Commercially available software PLAXIS 3D has made the analysis of prestressed geosynthetics simpler with much practical simulations of the ground conditions, saving valuable time and labour. Attempts have been made, so far to analyse the effect of prestressing geosynthetics with varying conditions such as the effect of shape of the footing, the effect of depth of the footing, effect of size of footing, effect of multiple geogrid layer, the effect of two square footing placed nearby on the load bearing capacity and the settlement characteristics of prestressed geogrid reinforced soil. The prestressed geogrid reinforced (PGR) has given almost 200% increment in bearing capacity with 66% reduction in settlement with respect to ordinary Geogrid Reinforced (GR) soil. Though circular footing has given lesser value of improvement for all the cases, the bearing pressure has been found to increase with increase in size of the footing as expected. The prestressing concept is valid for footing at different depths as well. The optimum number of geogrid layers has been found to be lesser for PGR soil than GR soil. The zone of adjacency for PGR soil has increased by 67% than Unreinforced (UR) soil and almost 25 % with respect to GR soil.