LOAD SETTLEMENT RELATIONSHIPS OF CIRCULAR FOOTING CONSIDERING DILATANCY CHARACTERISTICS OF DENSE SAND

Although the quantitative load-settlement relationships of spread foundation have been experimentally well demonstrated on sand ground, the underlying dynamic properties of the relationship remain to be elucidated. 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 of circular footing dense sand ground in soil tank with different volumes. The quantitative link of load and settlement was analyzed by FEM simulation with SMP-Cam-Clay model which was estimable of sand dilatancy. Comparison of the analytical data with the critical bearing capacity based on Terzaghi's theory lead to the following results: In the soil tank with a large volume and at Terzaghi's critical capacity, sand behavior shifts from continuous to discontinuous, and consequently results in total failure. With regards to a small tank, on the other hand, positive dilatancy exerts a marked binding effect of a soil tank rectangle. Accordingly, the dilatancy causes the increase of mean principal stress and the load exceeds the Terzaghi's critical bearing capacity.