Investigation of the raft-soil interaction with nonlinear finite element analysis

The raft-soil interaction is a subject that examines the effects of soil conditions on the foundation as well as the effects of foundation on the soil. In most of the studies on this subject, this interaction is neglected and it is assumed that the soil environment is infinitely rigid, and that the superstructure and the soil are fixed-supported. In this study, the raft-soil interaction was investigated in the design of raft foundations. In the aforementioned study, First of all, calibration analyzes of the finite element model were performed and the reinforced concrete design of raft foundation to be used in the finite element models were carried out with the traditional method. Superstructure load, soil stiffness and foundation thickness were taken into account as variable parameters in finite element analyzes, raft foundation performance and the effects of raft-soil interaction under different conditions were investigated. The internal forces, strains, settlements and contact pressure distributions obtained from the finite element analyzes were also compared with the ones obtained from the traditional method. As a result of the study, it has been thought that the factors that are not taken into account with the traditional assumptions are important in terms of raft foundation design and therefore the use of the traditional method for an ideal design may be insufficient. In addition, it was concluded that for an ideal raft design, the relative stiffness between the foundation and the soil should be taken into account, and punching control could be improved by considering the soil conditions.