Active Earth Pressure of Narrow Cohesionless Backfill on Inclined Rigid Retaining Walls Rotating about the Bottom

In engineering constructions, the backfill behind retaining walls is usually narrow, and its boundary conditions are asymmetric due to the space limitation. When the retaining wall rotates about the bottom, the direction of the principal stress also rotates due to the granular properties of soil and the multiple interfaces friction. Such phenomenon is more significant in narrow backfill, however, there are few studies about this. The finite element method analysis is able to demonstrate how the failure mode of narrow backfill and the rotation of principal stress are affected by the backfill geometry and interfaces friction. Theoretical analysis is employed here to calculate the principal stress rotation angle and lateral pressure coefficient of the interface element. Similarly, active earth pressure of narrow cohesionless backfill against inclined rigid walls rotating about the bottom, considering principal stress rotation and uniform load on the ground, is derived by differential element limit equilibrium, which, upon comparison with methods used in previous studies, is suitable for the asymmetric inclined boundaries and improves the scope and accuracy of calculation. Parametric studies herein show that increasing the new structure inclination and decreasing its friction will reduce the interference in the existing structure. (c) 2020 American Society of Civil Engineers.