Effect of facing stiffness on reinforced soil walls under surcharge loading–unloading

This paper investigates the impact of facing stiffness on the performance of geosynthetic-reinforced soil (GRS) walls under surcharge loading–unloading. Data from two instrumented physical model tests are utilised considering two different facing stiffness (block and wrapped). After the end of construction, the physical models were loaded and unloaded, step by step. They were comprehensively instrumented to monitor the load mobilised along with the reinforcements, horizontal toe load, lateral facing displacement, vertical displacement at the top of the walls and horizontal stress behind the block faces. In addition, a simplified analytical procedure is proposed in order to determine the maximum reinforcement load under surcharge unloading. The results show that the toe restraint at the base of the block-faced wall highly controls the performance of GRS wall with structural facing. When there is no toe resistance, irrespective of the facing type, the walls present, in general, similar performance under surcharge loading and unloading. Furthermore, during surcharge unloading, the reinforcement load near the face may be less affected in the wrapped-face wall compared with the block-faced wall. Moreover, the maximum reinforcement loads during surcharge unloading were fairly captured using the proposed procedure.