Structural Behavior of a Pile-Supported Embankment

The stress field in a pile-supported 3.9-m-high embankment was interpreted through three-dimensional finite-element modeling, and evaluated by field measurements involving strain gauges on the piles and earth pressure cells at the top and bottom of a 0.9-m-thick geogrid-reinforced platform. Analyses of the numerical results and the experimental data suggest that a vaultlike arch developed within the embankment, such that the vertical stress at the top of the platform was concentrated above the piles and virtually no vertical stress was measured between the piles. A similar situation existed within the platform, where an almost stress-free region between the piles was experimentally detected and numerically verified. From a structural point of view, a supporting skeleton was formed from a pile extension through the platform, a type of stress diffusion problem, and an arching effect appeared mainly in the embankment due to the very large stiffness of the piles in comparison to the surrounding media.