Numerical study on stress states and fabric anisotropies in soilbags using the DEM
Wrapping granular soils in geosynthetic containers, such as soilbags, results in a considerable increase in the bearing capacity due to the effective restraint on the dilatancy of the soil. We numerically investigates the stress states and fabric anisotropies in the wrapped soil using the DEM, providing a novel perspective for new insights into the reinforcement mechanisms and the development of constitutive relations for soilbags.
The two most anticipated loading conditions, namely, unconfined compression and simple shear, are considered, and numerical predictions are compared to experimental results. During unconfined compression, both global and local p–q stress paths evolve linearly, having the same slope until the global failure of the wrapping geosynthetic. Under simple shear, the global stress path approaches the critical state line first and then turns to the compression line of the wrapped soil. Some local loading–unloading stress paths are observed, which may account for the high damping of soilbags during cyclic shear. |
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Evaluating the performance of geotextile wrapped/layered granular soil: A comparative study using the DEM
The performance of geosynthetic-wrapped and -layered soil commonly used for constructing retaining structures are numerically investigates using the DEM. The geotextile and the soil that consist of the reinforced soil are calibrated with tensile, shear box, and triaxial test results. The discrete particle models of the two reinforced soils assume geotextile as regularly positioned particles linked with stretching springs.
The discrete models are loaded under triaxial compression in periodic boundary condition, in order to evaluate the influence of reinforcement form on the mechanical behavior of reinforced soil. The simulations show that the wrapped soil is able to sustain much greater stress than the layered one. Although similar global volumetric deformation is found in both cases, the soil wrapped in a container dilates less than that sandwiched between a pair of sheets. |