Application of the safety theory to the geotechnical design of piled raft foundations

Abstract

This paper reviews the principal calculation methods to estimate bearing capacity of piled raft foundations, selecting for further analysis the one with the closest results to field studies and numerical analysis. The application of the Limit State Method to geotechnical design of this kind of foundation is presented with the purpose of establishing a methodology for the calculation of bearing capacity of a piled raft. The partial coefficients necessary to introduce safety in this method are defined for the ultimate limit state. The application of the Safety Theory and probabilistic methods in the geotechnical design is presented, as well as the mathematic formulation for its implementation in piled raft foundation. A methodology for the adjustment of partial coefficients (to be used for the method of limit states) based on probabilistic methods is proposed. The expressions for this adjustment to be used in piled raft are obtained.