Design, Parametric analysis and Comparison of Geosynthetic Reinforced Retaining Wall with Cantilever Retaining Wall Using Finite Element Method (Case study of Jimma City)

Abstract

Soil is generally weak in tension and relatively strong in compression and shear. The concept of reinforcing a soil mass by incorporating a material that is strong in tensile resistance is similar to that of reinforced concrete. Through the inter-face friction, the reinforcement restrains lateral deformation of the soil next to the reinforcement and therefore increases the stiffness and strength of the soil mass. Geosynthetics have emerged as exciting engineering materials in reinforcing backfill soil of retaining wall. Due to this analysis and design of mechanically stabilized earth (MSE) wall is crucial this day. To do so finite element method is used to analyze the MSE wall. This research study is more concerned on determining and comparison of the stability of both MSE wall and cantilever retaining wall. For case study some representative soil samples were collected based on ASTM sampling procedures for the characterization of the soil under the retaining wall and backfill soil. The retaining wall were analyzed with plain strain model and 15-node elements are utilized. A total height Plaxis Version 8.2 is designed for two-dimensional modeling and analysis of physical space. In addition, parametric analysis of MSE wall also done. Global stability, facing panel deformation and tension force in the geogrid is calculated using Finite element method. The vertical deformation of MSE and cantilever retaining (CR) wall is 0.1m and 0.187m respectively. The horizontal deformation MSE wall and CR wall is 0.31m and 0.57 mm respectively. Factor of safety for global stability of MSE wall is 1.673 and cantilever retaining wall is 0.475. This shows by 78% the stability is improved. MSE wall is stable and suitable than GRS-RW for this site based on global stability and facing panel deformation. And sandy soil backfill material, PET type of geogrid is the safest for MSE wall construction. For very small construction area, and low geotechnical properties of soil site condition using MSE wall than CR wall is appropriate and the best.