A Three-Dimensional Discrete Element Modeling to Cyclic Response of Geosynthetic-Encased Stone Column

A three-dimensional discrete element modeling of cyclic behavior of geosynthetic-encased stone column (GESC) has been recently conducted to better understand the interaction between geosynthetic encasement and stone aggregates on a microscopic scale. Comparisons between numerical results and laboratory observations indicate a good accuracy of the modeling. Different responses of GESC like deformation characteristics (e.g., axial compression and radial expansion), stress state (e.g., stress and lateral pressure coefficient within the column) are monitored during the simulations for understanding the mechanics of the reinforcement mechanism. To decipher the mechanism of the macro behavior under cyclic loading, the variation of property parameters of stone aggregates on a micro-scale (i.e., porosity and coordination number) within four stages of a loading cycle has been investigated. The stiffness of GESC is found to be prominently improved under cyclic loading as a result of the densification of stone aggregates and increased confinement provided by the geosynthetic encasement.