Abstract ID: 3.12563 | Accepted as Poster | Talk/Oral | TBA | TBA

Mechanically stabilized earth (MSE) walls are gaining popularity in different parts of the world. These walls have demonstrated tremendous potential in supporting the rapid infrastructure development occurring in our country. This technology is highly versatile and is used for constructing highway approach roads, railway bridges, and airport runways in challenging terrains. MSE walls are generally designed using a 2D plane strain approach. However, recent observations indicate that these structures are extensively used in undulating terrains, where the 2D plane strain assumption is invalid—such as at turning corners of roads in hilly regions. Few studies have attempted to quantify the additional reinforcement requirements for these corners. Recent failures of reinforced earth structures, such as those at Yeager Airport (USA) and Sikkim Airport (India), highlight the need for improved design considerations. The geosynthetic-reinforced structure at Sikkim Airport exhibited extensive distress, primarily due to improper drainage design. Another contributing factor was the presence of a highly fractured phyllite rock mass at the base of this extremely high retaining wall. Similarly, the catastrophic failure of a 73 m high reinforced soil slope at Yeager Airport in Charleston, West Virginia, USA, was analyzed by VandenBerge et al. (2021), who concluded that improper engineering judgment and local stress concentrations were the primary causes of failure. For infrastructure expansion in tough hilly terrains, integrating airways and highways while minimizing environmental impact is crucial. Life Cycle Assessment (LCA) studies highlight the importance of using locally available materials, as MSE wall design parameters generally allow for draining backfill material. However, contractors often opt for locally available soil, which may be highly cohesive. To ensure safety, researchers tend to adopt high factors of safety (FOS). In the present research, numerical modeling using Plaxis 3D will be employed to study corner stress development in MSE walls—an aspect that remains hidden in 2D limit equilibrium method (LEM) software such as Rocscience Slide. A numerical analysis of 26 cross-sections of MSE walls was conducted for a RESA project in the hilly terrains of Northeast India (Pakyong Sikkim).