An investigation of failure modes for geosynthetic reinforced column supported embankments

Current design procedures for geosynthetic reinforced column supported (GRCS) embankments only consider the sliding failure for external stability and the shear failure of deep cement mixed (DCM) columns for internal stability. It is recently found that there are some other failure modes such as collapse failure, slip circle failure, punching shear failure around column heads (overall or local), and bending failure of DCM columns are also significant for GRCS embankments. However, still there are uncertainties in identifying the critical failure modes for these embankments. Hence, this paper investigates some failure modes for GRCS embankments using the Finite element method (FEM). The embankment and traffic loads are gradually increased to bring the model to the verge of failure. Bending failure of DCM columns and subsequent shear failure for internal stability, local punching failure, overall punching failure and excessive total settlement failureare identified from the finite element analysis results and discussed in detail.