Reliability analysis of a piled raft accounting for soil horizontal variability

The spatial variation of soil properties induces foundation stresses and/or displacements that cannot be predicted when assuming soil homogeneity. A numerical model of a piled raft foundation has been developed to describe how the soil–structure interaction can be influenced by the horizontal soil variability. The structural response of the system is analysed using Monte-Carlo simulations. The results are very different from those obtained with usual engineering models, for the raft design as well as for the pile design. Some guidelines are given for developing a half-way design approach, combining the simplicity of modeling with the possibility to account for the main effects of soil heterogeneity and of soil–structure interaction on the system reliability.