Evaluation of the effects of facing stiffness and toe resistance on the behavior of GRS walls

This article presents physical and numerical model studies in order to assess the effects of facing stiffness and toe resistance on the behavior of GRS walls. Experimental tests were performed in a facility at the Geotechnical Laboratory of COPPE/UFRJ, using block and wrapped facing types. Tension along the reinforcements and the lateral and vertical movements of the walls were monitored. The results show that for the condition of no toe resistance facing stiffness may not significantly affect the mobilized tension in the reinforcements. Nevertheless, when the base of the face is restricted, varieties of facing stiffness may play an effective role in the magnitude of the tension in the reinforcements. The magnitude of reinforcement tension is not solely associated with facing stiffness, but also to the mobilized friction at the interface of the base of the facing column and foundation soil. Lateral displacements observed in the wrapped-faced wall were much greater than those verified in the block-faced wall, and this may be related to local movements near the face of the walls. Numerical modeling shows that the summation of the maximum tension in the reinforcements and toe load in fixed base condition remained almost constant (less than 5% of variation) and is greater than the value for a free base condition, irrespective of the magnitude of facing stiffness. This difference in the determined values for walls with a free and fixed facing base may be attributed to the lateral movement of the walls, which is more restricted in a fixed base condition.