Deformation Characteristics and Potential for Rationalized Design of Geosynthetics-Reinforced Soil Retaining Walls with Rigid Facing

Abstract

Geosynthetics-reinforced soil retaining walls with rigid facing (GRS-RWs) have been widely adopted in railway infrastructure in Japan. The current design methodology integrates mechanically based stability and deformation analyses with empirically determined structural details. To extend their application to non-railway infrastructure and overseas projects with different performance requirements and construction conditions, a more rational and adaptable design approach is required. This study aims to contribute to such rationalization by experimentally investigating the load-resistance mechanisms of GRS- RWs, focusing on the roles of wall facing, backfill soil, and reinforcements. A series of model tests was conducted in which vertical cyclic loading simulating train loads was applied behind the wall facing. The displacements of the wall facing and backfill, earth pressures acting on the facing, and tensile forces mobilized in the reinforcements were measured. The results reveal that, contrary to conventional understanding, larger earth pressures acting on the rigid facing do not degrade performance but instead improve deformation resistance through increased confining pressure. In regions where very high seismic performance is not required, wall facing specifications, including stiffness and thickness, may be rationally simplified without significantly degrading overall performance. In contrast, reinforcement stiffness and vertical spacing strongly influence confining pressure, earth pressure, and load distribution. These findings highlight the importance of controlling reinforcement parameters and backfill conditions to ensure stability and deformation performance of GRS-RWs.