Finite Element Method Analysis Applied to Different Foundations Structures Systems

In the conventional static analysis of building frames, the base is idealised on rigid supports and the building is subdivided into three parts namely, the superstructure, the foundation and the ground soil, before design. In real life situations, the soil underneath the building undergoes deformations which may alter the performance of the structure. In this paper, it is studied the effect of soil type and foundation type on the response of a building frame system with both fixed base and flexible base. The Winkler model of soil-structure interaction is adopted to study the influence of soil flexibility and foundation rigidity on a 4 storey RC building with a regular plan resting on three types of soils namely, the light peat marshy ground, wet clay and medium gravel with fine sand. Three types of foundations are considered in the study: isolated footings, tied foundation and the raft (with and without overhangs) foundations. Winkler model is developed using springs by Finite Element Method in SAP2000. The settlement, the bending moment, the shear force and the axial force are the parameters placed forth for the comparative study. Results obtained reveal an increase in the response of the structure with respect to the soil flexibility and foundation rigidity.