Load Settlement Relationships of Circular Footings Considering Dilatancy Characteristics of Sand

Abstract

In order to elucidate the mechanical properties of load-settlement relationships of spread foundations on sand ground, experimental and analytical study on strain hardening and dilatancy of sand is needed. Here we present the theoretical properties which were derived from circular footing model experiment and computer simulation. The model experiment was carried out through vertical loading on circular footing, and used relative density and tank dimensions as parameters.The quantitative relationship between load and settlement was analyzed through FEM simulation with SMP-Cam-Clay model, which is capable of estimating the dilatancy of sand. The results are summarized as follows;In both cases of dense and loose sand models, before reaching the ultimate load, the load-settlement relationship obtained from FEM simulation corresponded with that of obtained from the experiment.Afterreaching the ultimate load, “Terzaghi’s bearing capacity line”corresponded with the load-settlement relationship obtained from the experiment.In the case of medium-dense sand models,some binding effect of a soil tank rectanglewas recognized. The effect was considered to be exerted by the positive dilatancy of the sand, which occurred steadily with the settlement progresses.