Shear Strength Characterization of the Interface Between Geocell Walls and Infill

This study focuses on the evaluation of results from direct shear tests conducted to characterize the interface between geocell walls and various infill materials. Tests involved geocells from five different products, manufactured using high-density polyethylene (HDPE), novel polymeric alloy (NPA) and polypropylene (PP) nonwoven geotextiles. Two types of infill material (coarse and fine-grained soils) were adopted, along with different compaction conditions and grout to determine the interface shear strength under various conditions. The testing program also included varying the texture of the geocell walls as well as the number of perforations. Surface roughness profilometer tests were conducted to evaluate texture parameters. The analyses focused on the interface strength, obtained for both peak and post-peak conditions, characterized by the ratio between the interface friction angle and the soil peak friction angle. The results indicate that the presence of texture on the geocell wall led to comparatively high frictional efficiency, although the type of texturing was found not to have a significant effect on the frictional capacity of the geocells evaluated in this study. Additionally, the experimental results indicate that a perforation fraction of up to 10% of the total cell wall area did not significantly affect the interface shear strength. Based on the experimental program performed, a geocell with textured and perforated walls was found to lead to improved interaction with the infill material.