Failure mechanisms in geosynthetically reinforced soil slopes

Centrifuge tests were used to investigate the failure mechanisms of geosynthetically reinforced steep soil slopes and to evaluate the assumptions in their design. The moment of failure was defined by a sudden change in the rate of settlements at the crest of the slope, as monitored from transducers placed on top of the centrifuge models. Failure in the models was characterized by well-defined curved sheer surfaces through the toe of the slope, which is in good agreement with current design methods for reinforced slopes based on limit equilibrium. However, in contrast to the current design assumptions that failure should develop from the toe of the reinforced slopes, failure was observed to initiate at midheight of the slopes. Consistent with the experimental observations, a new distribution of reinforcement forces with depth is proposed for the design of geosynthetically reinforced soil slopes.