Effect of Foundation Shape on Settlement by Numerical Method

Abstract

Five prototypes arranged in three different soil conditions is presented to find out the load-settlement relationship of soil and foundation. For creating three types of condition two types of managed soils are stiff clay and soft clay. The five prototypes used here represent the condition of shallow foundation. Prototypes area being same for cases has the shape of Triangular, Square, Rectangular, Pentagonal and Hexagonal. The load-settlement behavior has been found out plan-wise using Plaxis 3D software. Geotechnical engineering software which uses finite element method and Mohr-Coulomb failure criterion following mathematical differential equational problems. Plaxis 3D software uses the properties of soil cohesion, angle of internal friction, Elasticity modulus and unit weight, elasticity modulus of the foundation to settle a relation for the interaction between soil and foundation. Load-settlement behavior for the five prototypes as tried to be found out by Plaxis 3D has represented the immediate settlement of soil on which the prototypes have been rested. The graphs also help to understand the difference in the bearing capacity and settlement for the five prototypes, each of which acted as foundations. Pressure bulb is an effect of vertical pressure which differs from shape to shape of foundation. It directly affects the intensity of pressure and the intensity of pressure affects the settlement. The bearing capacity also affects the settlement. A triangular foundation has the best bearing capacity as its settlement is the lowest. But as a triangular shaped foundation is not practically used and not ideal it is not used for structural work. This study shows that square or rectangular foundation is best for a structure due to higher bearing capacity and lesser settlement compared to the same of pentagonal and hexagonal shaped foundation. But if comparison is done between square and rectangular shaped foundation, square is the best.