Analysis of Raft with Frame on Two Layered Foundation

The objective of this paper is to analyse a space frame-raft-soil system under static load to understand the influence of layered soil (2 layers) on the behaviour of a soil-raft and frame. In the analysis, all three components -- space frame, raft and soil -- were considered as a single compatible unit. The analyses are carried out for linear and non - linear conditions, in which soil is treated as a homogeneous and isotropic continuum. The analyses are carried out by ANSYS¹⁰ finite element code. The non -linear behaviour of soil was incorporated through multi - linear isotropic model (MISO) of ANSYS. The results of two different layered soils are compared, and the influence of the layered soil on settlement, the bending moment and contact pressure are studied. Parametric study was also carried out by interchanging the properties of the soil layers, modulus of soil and thickness of raft. The results of two different raft thicknesses are compared, and the influence of the raft thickness on settlement, the bending moment and contact pressure are also studied. The increase in raft thickness resulted in reduced settlement, an increased bending moment, and reduced uniform contact pressure. The results of three soils with different Young's modulus are compared and the influence of Young's modulus on settlement is also studied.