The effect of Encapsulation in Sand Layer and Application of End-Bend on Pullout Resistance Enhancement of Polymeric Strap in Clay

Authors

1 Civil and Environmental Engineering Department, Shiraz University of Technology, Shiraz, Iran

2 Department of Civil and Environmental Engineering, Shiraz University of Technology, Shiraz, Iran

10.22034/ceej.2025.64913.2403

Abstract

In recent decades, reinforced soil retaining walls have gained popularity due to their ease of construction and low costs. Utilizing polymeric straps for soil reinforcement provides a straightforward and economical way to enhance the strength and deformation characteristics of retaining earth walls. However, these polymeric straps lack adequate pullout resistance, owing to the absence of transverse members. To address this issue, a U-shaped end-bend can be added to the strap, which creates a surface that enhances passive resistance. Although construction codes generally emphasize the use of high-quality granular materials as backfills for reinforced soil retaining walls, many construction projects are characterized by local soils that consist of marginal cohesive materials, making them unsuitable for backfills. A promising solution to reduce project costs in reinforced wall construction is the sandwich method, which involves encasing the reinforcement in a thin layer of granular soil within the backfill. This technique not only improves the pullout resistance of the reinforcement but also allows the enclosed layer to serve as a drainage system. This research investigates the pullout behavior of straps with both direct and U-shaped ends in sand and clay backfills through a series of large-scale pullout tests. Additionally, the impact of the sandwich method on enhancing the pullout resistance of U-shaped polymeric straps is examined.

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References

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