Centrifuge Modeling of Geotextile-Reinforced Cohesive Soil Retaining Walls

Twenty-four reduced scale models of vertical and steeply sloping (1 H :6 V ) reinforced soil walls were built using kaolin as the backfill, reinforced with a nonwoven geotextile simulant, and loaded to failure under increasing self-weight in the geotechnical centrifuge. Models were constructed on either firm or rigid foundations, and different lengths of reinforcement were tested. No pullout failures were observed in any models. In vertical walls failure developed entirely within the reinforced zone when L /H≥ 0.75; in the steeply sloped walls this threshold occurred when L /H≥ 0.67. Models on firm foundations showed better performance than identical models built on rigid foundations. A stability analysis using the simplified, two-dimensional limit-equilibrium simplified Bishop method incorporating reinforcement was found to be a good predictor of the behavior of the models based on calculated factors of safety at failure. The development of tension cracks in the backfill as walls underwent prefailure deformations led to stress concentrations in the geosynthetics and should be avoided in practice.