Effect of Earth Pressures and Shear Key on the Structural Stability of Gravity Retaining Wall Supporting Anisotropic Soil
Authors: Salahudeen AB, Ketkukah TS
Constructing a retaining wall is very expensive. The cost is directly proportional to the cost of different elements like volume of excavation and concrete. Thus, it is very important for engineers to design optimum and safe retaining walls. The objectives of this study are to evaluate the implications of the two classical lateral earth pressure theories on gravity retaining walls and to determine the effect of shear key depth and location (toe, stem and heel) on the general stability of the wall. The earth pressures acting on a retaining wall supporting an anisotropic cohesionless soil was estimated by the earth pressure theories proposed by Rankine and Coulomb and compared with that obtained by finite element method (FEM) using Plaxis 2D. Results revealed that the method proposed by Coulomb yielded higher active and passive lateral earth pressures than that of Rankine. The values provided by Rankine method are constantly below those of FEM. A peak active and passive earth pressure values of 92.3 kN/m2 and 3254.95 kN/m2 were obtained. It was observed that the depth of shear key is significant for safety factor against sliding. At wall friction angle factor of 0.6, only the situations with shear key depths of 1.6 and 2.0 m met the minimum safety factor against sliding of 1.5. It was observed that positioning the shear key at the heel or at any position between the stem and the heel is the best practice which was recommended to enhance higher safety against overturning failure of the wall.
Affiliations: Department of Civil Engineering, University of Jos, Jos, Nigeria.
Keywords: Anisotropic Soils, Finite Element Method, Gravity Retaining Wall, Lateral Earth Pressures, Shear Key
Published date: 2019/12/30