The Impact of Using Geogrid Capsules on The Bearing Capacity of Strip Foundations in Sandy Soils

Document Type : Research Article

Authors

Department of Civil Engineering, Faculty of Engineering, Hamedan Branch, Islamic Azad University, Hamedan, Iran

Abstract

Soil is a material that exhibits good compressive strength but is weak under tension. To overcome tensile weakness and enhance shear strength, various soil improvement techniques are employed. Soil reinforcement is a common technique that uses natural or synthetic materials for this purpose. In recent years, materials like geosynthetics have seen significant development in soil reinforcement. Among the most common synthetic reinforcements are geogrids, which mobilize the friction at the interface between soil and reinforcement materials, thereby increasing both the tensile and shear strength of the soil. This study examines the effect of geogrid capsules on the bearing capacity of strip foundations on sandy soils. The force-settlement variations were modeled and analyzed using the PLAXIS 2D finite element software to conduct sensitivity analysis for the research variables. In this study, after validating the numerical model, the impact of parameters such as capsule length, thickness, number of layers, distance from the foundation, and spacing between capsules on the ultimate bearing capacity of the strip foundation was investigated. The results of these analyses were presented in the form of dimensionless graphs, from which the optimal depth of placement, thickness, and number of encapsulated reinforcement layers were determined. The analysis results indicate that the use of geogrid capsules significantly improves the soil reinforcement outcomes compared to geogrid sheets. Additionally, increasing the number of capsule layers considerably enhances the bearing capacity of the strip foundation, with the highest bearing capacity observed at a depth ratio of 0.1. Ultimately, increasing the length and number of capsule layers results in higher bearing capacity and reduced settlement, due to the prevention of failure surface development beneath the capsule. Consequently, the optimal length and thickness of the capsule were determined.

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References

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Amirkabir Journal of Civil Engineering
Volume 57, Issue 2
2025
Pages 341-362

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