Numerical Investigation on Seismic Performance of a Piled-Raft Foundation with Grid-Form DMWs

Abstract

AbstractIn this paper, the seismic performance of a piled raft foundation combined with grid-form deep mixing walls under a strong earthquake is investigated numerically. A 12-story building on the soft clay ground was modeled using a three-dimensional finite element soil–structure interaction model. The model was calibrated using the seismic observation records of a middle-scale earthquake at the building site in the previous study. The elasto–plastic model used for the stabilized soil has the tensile criteria and the shear criteria, and the model has an ability to evaluate the post-peak softening. The analysis result indicates that the induced stress reaches the tensile strength in some parts of the deep mixing walls. However, few parts of them lose large amount of tensile strength as a result of post-peak softening. And the grid-form deep mixing walls are found to keep their function of reducing the bending moment of the piles to an acceptable level.KeywordsPiled raft foundationDeep mixing wallsSoil and structure interaction