Numerical Investigation of the Field Performance of Geosynthetic-Reinforced Walls with Secondary Reinforcement

This paper presents the results of a numerical study conducted to investigate the field performance, under working stress conditions, of an instrumented full-scale geosynthetic-reinforced soil (GRS) wall with secondary reinforcements. The numerical analyses aim to simulate the monitored field performance, with a particular focus on the impact of the facing-reinforcement connections, compaction-induced stresses, and the inclusion of secondary reinforcements. Two connection conditions, representing the upper and lower bounds of connection mobility, were considered. In addition, stresses induced by compaction operations were incorporated into the numerical simulations. Overall, the results demonstrate that the numerical predictions accurately captured the field-monitored performance. In particular, the results show that the connection type (tight versus loose) locally affects the reinforcement strains within a region of up to 1 m from the wall face, with tight connections resulting in higher connection strains and increased lateral earth pressures. However, the connection conditions were found to have a negligible impact on the magnitude of the maximum reinforcement tension and on the vertical earth pressures beneath the GRS structure. Additionally, accounting for compaction-induced stress in the simulation resulted in a reduction of both vertical and horizontal postconstruction movements under surcharge loading. Although secondary reinforcements are often not considered in conventional internal stability design assessments, this study shows that their inclusion decreases the unit tension mobilized by the primary reinforcement, resulting in lower connection strains and maximum unit tension in the primary reinforcements. Finally, secondary reinforcements were found to lead to a reduction in both lateral displacements and vertical earth pressures near the wall facing.