Estudo de caso do efeito tridimensional e de grupo de estacas cravadas em areias

Abstract

This research deals with the installation and group effect of piles in sand. The installation of displacement piles in sand causes a reduction of the soil void ratio in the surrounding mass, much more intense as closer the pile axis. Depending on the relative spacing between pile axes, soil improvement by reducing the void ratio is more significant. The behavior of the group under load will change due to installation, in addition to the group effect. From a very well documented database, the research initially established some correlations for the determination of the modulus of soil elasticity as a function of the confining pressure and the relative density which is related to the void ratio. The methodology of soil improvement as a function of the relative spacing between piles was simulated, both for the case of isolated piles and also in pile group. The behavior with and without soil improvement was compared to the experimental results in small model tests. In some cases, the agreement between the numerically simulated behavior resulted in reasonably accurate approximations when compared to the experimental results. In the case of a group in a block, the numerical results presented a soil resistance, on the block in contact with the soil, in excess of the experimental values. The results are compared and discussed aiming at contributing to this research branch. Applications to new cases, preferably on a natural scale, are recommended.