Interface Shear Behavior of Geofoam-Sand: A Comprehensive Laboratory Investigation: Fid-Bau Portal

Interface Shear Behavior of Geofoam-Sand: A Comprehensive Laboratory Investigation

Sreekantan, P. G. / Bansal, Deepesh / Ramana, G. V.

The interaction between soil and geosynthetics is crucial in geotechnical engineering, profoundly impacting the stability and performance of infrastructure projects. Geofoam, a lightweight and high-strength cellular foam block, has emerged as a popular choice in vertical road embankments due to its advantageous properties. Despite its widespread use, understanding the interface behavior between soil and geofoam remains essential for optimising design and ensuring long-term performance. This study examines various parameters that influences the shear behavior of the geofoam-sand interface such as normal stress, geofoam density, hardness, and roughness. Laboratory shear tests and image-based analysis were conducted to explore these parameters. In addition to inherent roughness variations with density, alterations in roughness were achieved by introducing ledges of varying sizes and shapes into the geofoam. Findings reveal limitations in conventional test configurations, emphasising the need for a modified setup to obtain accurate interface friction angles. The interface friction angle typically ranges from 16^o to 24^o, with an adhesion of 1–2 kPa for ledged interfaces. Furthermore, novel insights into the impact of geofoam hardness and surface roughness on interface behavior were unveiled, addressing gaps in previous research. This study advances the understanding and application of geofoam materials in geotechnical applications and provides recommendations for optimising interface design, including the selection of optimal ledge size and geometry. These insights are crucial for improving the performance and reliability of geotechnical structures involving geofoam.