PERFORMANCE OF RING FOOTING RESTING ON REINFORCED MULTILAYERED SOIL USING PLAXIS 2D

A.I. Dhatrak, P.C. Mishra

Abstract: Ring footings are efficiently and economically applied as foundation for axis symmetric structures. This paper serves a numerical study to find out t h e p e r f o r m a n c e of model ring footing resting on reinforced multilayered soil. The software PLAXIS 2D is used for the analysis which works on one of the best method of numerical analysis i.e. Finite element Method. Geogrid is used as soil reinforcement. The analysis was based on Mohr-Coulomb’s criterion for soil. The inner to outer diameter ratio of ring footing chosen are 0.2, 0.4,0.6 and 0.8. The parameters considered for analysis are Geogrid number of layers, soil layers and different inner to outer diameter ratio of ring footing are investigated. The ultimate bearing capacity and settlement reduction was calculated for different number of reinforcement layers and radius ratio. From it is found that there is a considerable improvement in load carrying capacity and increase in settlement reduction ratio when reinforcement is provided in layers. The load carrying capacity of ring footing is found to be maximum at a radius ratio 0.4. For this radius ratio, when the reinforcement is provided in single layer, the bearing capacity improvement is found to be 110% . For two layer and three layer reinforcement 250% and 300% bearing capacity improvement is noticed for radius ratio 0.4. For fourth to seventh the improvement in the bearing capacity is around 10%. The settlement reduction is found to be around 40 to 50% for three layer reinforcement and for further reinforcement layer settlement reduction is around 5%.

Keywords: Ring Footing, Multilayered Soil, Geogrid, Bearing Capacity, Settlement Reduction Ratio

DOI: https://doi.org/10.15623/ijret.2016.0505004