Laboratory investigation of nonuniformly reinforced soil-retaining structures

Vertical and sloping model walls and steep slopes were built with uniform and nonuniform geotextile and backfilled with cohesive clay soil and tested to failure using a geotechnical centrifuge. The results demonstrate an overall better performance for nonuniformly reinforced models compared to the uniformly reinforced walls and slopes with equal reinforced volumes in terms of postponing the development of tension crack, increasing the prototype equivalent height at failure, and improving the reinforcement effect. These effects were more dominant for vertical walls than for slopes of 63.4 degrees (1H:2V). However, the uniformly reinforced walls and slopes showed a better sign of warning prior to failure. Limit equilibrium stability analysis using the simplified Bishop method incorporating tangential and/or horizontal reinforcement was found to be a good predictor of model behavior The implications of this investigation will have practical significance in cost-effective widening of existing highway and railway embankments.