An approximate numerical analysis of rafts and piled-rafts foundation

The load distribution and deformation of rafts and piled rafts were investigated by an analytical and numerical studies. Special attention is given to the improved analytical method (MEGA piles) proposed by considering raft-pile flexibility and soil-pile nonlinearity. The response of raft, a three-dimensional, thin-plate substructure that bears on the soil, is analyzed by flat shell approach by combining a membrane element with a Reissner-Mindlin plate element. An improved analytical method is also developed for the design of piled raft. A series of numerical analyses on piled raft were performed for different head connected conditions, asymmetric geometry of raft, raft flexibility, pile diameters. The proposed method has been verified by comparing the results with other numerical methods and a field case study. Through comparative studies, it is found that the proposed method represents a significant improvement in the prediction of piled raft load sharing and settlement behavior.