ANALYTICAL STUDY OF A RAFT FOUNDATION BY DIFFERENT MODELS

Abstract

In case of transmission towers it is often seen that allowable pressure on soil are significantly low for individual footings to distribute the structural load through the foundation area. Alternatively when soil contains compressible lenses or the soil profile is erratic, it is difficult to define and assess the extent of each of the weak pockets or cavities, in these situations raft foundation is required to incorporate effect of overall settlement. In the present study the raft foundation is analyzed by different approaches using Staad pro and simplified models. The relative stiffness of the foundation is directly proportional to the thickness of the raft; hence in the present work thickness of raft is modified as per the relative stiffness. A number of combinations of relative stiffness and baring capacity are considered to obtain shear force and bending moment. It is observe that Staad pro gives higher bending moment and shear force under the explained set of conditions considere...