Structural Behavior of Concrete Retaining Walls with Shear Keys at Different Positions

This study investigates the structural behavior of reinforced concrete cantilever retaining walls incorporating shear keys under static loading conditions using three-dimensional finite element analysis in ANSYS Workbench. The primary objective was to evaluate the influence of shear key provision on stability parameters such as sliding resistance, deformation, strain distribution, and stress concentration. A retaining wall of 4.0 m height and 2.4 m base width was modeled under active earth pressure of 48 kN calculated using Rankine’s theory. The baseline model without a shear key was found to be safe against overturning (Factor of safety = 2.97) but unsafe against sliding (FS = 1.26 1.5). Finite element results showed maximum equivalent strain of 0.04032 mm/mm, deformation of 5.7 mm, normal stress of 2.4 × 10⁷ Pa, and shear stress of 8 × 10⁶ Pa. The introduction of a shear key significantly improved performance, reducing strain to 0.00488 mm/mm and deformation to 4.2 mm. Further enhancement with bolted shear key configuration yielded the lowest strain (0.003629 mm/mm), deformation (3.8 mm), normal stress (1.15 × 10⁷ Pa), and shear stress (1.5 × 10⁶ Pa). The findings confirm that shear key incorporation effectively enhances sliding resistance, improves stress redistribution, and increases overall structural stability, providing a safer and more economical retaining wall design solution.