NUMERICAL STUDY OF BEHAVIOR OF SQUARE FOOTING ON GEOGRID-REINFORCED FLYASH BEDS UNDER STATIC LOADING

The technique of ground improvement using geosynthetics has been developed extensively over the last few decades, in particular to those applied in pavement and foundation engineering. Fly ash is a naturally-cementations coal combustion by-product. Coal-based thermal power plants all over the world face serious problems of handling and disposal of the ash produced. Hence attempts are being made to utilize the ash rather than dump it. The main objective of this research study is to investigate the potential benefits of using the reinforced soil foundations to improve the load carrying capacity and reduce the settlement of shallow foundations on flyash. Numerical modelling is performed using PLAXIS version 8.2 which is finite element code for soil and rock analysis and is capable of modelling reinforced soils. A series of finite element analysis were performed to study the effectiveness of the reinforcement distribution (i.e, number of reinforcement layers and the spacing between the reinforcement layers) on the behaviour of the square footing on flyash beds. The dimensions of the tank used in analysis are 11m diameter and 3.6m height. The mild steel footing is used with the dimensions of 1m width and 0.04 m thickness respectively. The loading condition used for the present study is Point load. The input values of point loads are given in force per unit width (kN/m). The static loads are applied up to 50mm settlement. The analysis demonstrates that the reinforced flyash beds perform better than the unreinforced flyash beds. The performance of footing improves with increase in number of reinforcement layers. As the spacing between the reinforcement increases settlement will reduces.