Optimization of preloading in MSE walls: numerical and experimental analysis

The performance of reinforced soil structures is strongly influenced by loading conditions, yet the combined effects of different scenarios on full-scale Mechanically Stabilized Earth (MSE) walls remain underexplored. This study investigates how variations in surcharge load width, magnitude, direction, and location, applied before a strip footing load, affect wall deflection and reinforcement tensile forces. Numerical analyses were performed on MSE wall models with flexible and rigid facings and compared with full-scale experimental results. A two-step loading process was used: an initial heavy, high-frequency compaction-induced preload followed by a concentrated strip footing load. To simulate dynamic loading effects, two preloading strategies were examined: (1) sequential application across the backfill (Type I) and (2) discrete location loading (Type II). Increasing preload width significantly reduced maximum deflection, with single-point loading achieving performance comparable to distributed loading. Optimal performance occurred when the preload was applied near the wall face over a width representative of the drum contact area in compaction tests, resulting in substantial reductions in wall deflection and reinforcement tensile forces. Numerical predictions matched experimental results, validating the approach and providing practical guidance for optimizing preloading strategies to improve MSE wall performance under varied operational conditions.