University of Qom Civil Infrastructure Researches 2783-140X 5 2 2020 02 20 Investigating the Effect of Geocell Changes on Slope Stability in Unsaturated Soil Investigating the Effect of Geocell Changes on Slope Stability in Unsaturated Soil 137 151 1493 10.22091/cer.2019.4270.1147 FA Behnam Mehdipour Department of Civil Engi-neering, Najafabad Branch, Islamic Azad University, Najafabad, Iran. 0000-0003-0308-9357 Bahram Nadi Department of Civil Engi-neering, Najafabad Branch, Islamic Azad University, Najafabad, Iran Hamid Hashemalhosseini Civil Engineering Group, Is-fahan university of technol-ogy, Isfahan, Iran Masoud Mirmohammadsadeghi Departeman of water and natural Environment, Isfahan Higher Education and Re-search Institute (IHEARI); Mimistry of Energy, Isfahan, Iran Journal Article 2019 04 19 The purpose of this research is to investigate the performance and efficiency of reinforced slope in the stability of geocell layers in unsaturated soil conditions. Slope reinforced with geocell, due to the fact that the geocell has a height (three-dimensional), acts as a beam in the soil, and because of its flexural properties, it has a moment of inertia as well as bending strength, which reduces the displacement and increases the coefficient reliability of the slope. Considering unsaturated conditions of soil contributes a lot to make results close to reality. One of the well-known models among elastoplastic mod-els for modeling unsaturated soils is Barcelona's basic model, which has been added to the FLAC2D software by codification. Changes in thickness, length, and the number of geocell layers are remarkably effective on slope stability. The results show that the geocell's reinforcing efficiency depends on the number of layers and the depth of its placement. As the depth of the geocell's first layer increases, the lateral and vertical side elevation of the upper part of the slope increases with respect to the elevation. Load capacity increases with increasing geocell length. By increasing the length of the geocell lay-er, the joint strength, the tensile strength of the mobilized, and the bending moment are increased. Also, by increasing the thickness of the geocell, the amount of moment of the inertia increases, and as a result, the amount of geocell reinforcement bending moment increases. The purpose of this research is to investigate the performance and efficiency of reinforced slope in the stability of geocell layers in unsaturated soil conditions. Slope reinforced with geocell, due to the fact that the geocell has a height (three-dimensional), acts as a beam in the soil, and because of its flexural properties, it has a moment of inertia as well as bending strength, which reduces the displacement and increases the coefficient reliability of the slope. Considering unsaturated conditions of soil contributes a lot to make results close to reality. One of the well-known models among elastoplastic mod-els for modeling unsaturated soils is Barcelona's basic model, which has been added to the FLAC2D software by codification. Changes in thickness, length, and the number of geocell layers are remarkably effective on slope stability. The results show that the geocell's reinforcing efficiency depends on the number of layers and the depth of its placement. As the depth of the geocell's first layer increases, the lateral and vertical side elevation of the upper part of the slope increases with respect to the elevation. Load capacity increases with increasing geocell length. By increasing the length of the geocell lay-er, the joint strength, the tensile strength of the mobilized, and the bending moment are increased. Also, by increasing the thickness of the geocell, the amount of moment of the inertia increases, and as a result, the amount of geocell reinforcement bending moment increases. https://cer.qom.ac.ir/article_1493_6c9de07beb639351c5ab75d4c9e497b7.pdf