LOAD SETTLEMENT BEHAVIOUR OF SQUARE PLATE IN SANDY SOIL MIXED WITH FINE GRAVELS AND ITS NUMERICAL MODELLING IN ABAQUS 6.10

Abstract

This project work evaluates the benefits of plate load test in investigating the effect of density of coarse sand and fine gravels mixed it with the shape and size of the plates on the bearing ability of soil. The plates used in this test is square shaped with dimension 100mm, 150mm & 200mm. For conducting the tests, a steel box of size 40cm x 70cm x 50 cm has been modelled. The effect of density can be studied by conducting tests at various densities i.e. 19.28 KN/m3, 21.42 KN/m3 and 25 KN/m3 by giving 50, 100 & 150 number of blows respectively. The effect of fine gravels can be studied by mixing different percentages of fine gravels i.e. 8% , 16 % and 24% by weight in the coarse sand. The same model has been modelled in the finite element software Abaqus 6.10 with the elastic analysis to compare its result with the experimental analysis. The scale effect of the box has also been studied in this project. For this purpose, the plate load tests were performed on the large sized box of size 1.5 m x 1.5 m x 0.8 m. This has been done to nullify the boundary effects of the small sized box. The experimental result indicates that with increase in the density of sand, the footing settlement keeps on decreasing. Also the bearing capacity can be improved by adding fine gravels. It has been found that with increase in the size of square plate , the settlement of footing keeps on increasing. It is also observed that at any level of pressure , the settlement was found to be less in case of square plate as compared to that of circular plate. This observation is valid for any mix i.e. soil blended with different percentages of aggregates. This is also true for any plate size. It has also found out that the theoretical modelling results are less conservative than the experimental results.