Performance of multi-tiered mechanically stabilized earth walls under static loading

Reinforced soil has been widely used in civil engineering for various infrastructure applications, including retaining walls, bridge abutments, foundations, support structures for highways, and railways. This study focused on examining the fundamental behavior of mechanically stabilized earth (MSE) walls using numerical modeling technique in the PLAXIS 2D software. The investigation includes the impact of tiered configurations, such as single-tiered, two-tiered, and three-tiered wall systems. Increasing the number of tiers showed lower displacements about 22% and improved stability. The influence of offset distances between tiers is further explored for two-tiered and three-tiered walls. Increase in offset distances showed decrease in displacements about 23% and improved stability by reducing the axial force distribution by 51% in two-tiered walls and 26% in three-tiered walls compared to single-tiered wall. Furthermore, the study investigated the effects of reinforcement stiffness and spacing between reinforcements. Keeping the length of the reinforcement in accordance with load to be applied and based on the findings from these analyses, the geometry of the MSE walls is fixed with the obtained optimum parameters such as offset distance and stiffness of reinforcement for application of different magnitude of surcharge loads. Surcharge loads of more than 200 kN/m resulted in FOS less than 1.5 stating the feasibility of potential failure of even multi-tiered walls with reinforcement of larger stiffness and closer spacing.