Soil-geocell interfacial interaction subjected to different strain rates: Macroscopic and microscopic observations

Reinforced soil structures exhibit enhanced stability owing to the induction of tensile strength into the soil system through the usage of reinforcements. Shear stresses developed in the soil system are transferred to the reinforcement as tensile forces via friction at the soil-reinforcement interface. This interaction remains consistent under static or monotonic loading conditions but is subjected to variation under seismic activity due to the strain rates imparted by the seismic wave propagation. In this paper, the interaction at the soil-geocell interface is studied by conducting interface shear tests under different strain rates. Surface abrasion resulting from the specimens subjected to shear under varying strain rates is assessed. The results indicate that higher strain rates do not affect the interface strength for dense specimens, thereby depicting a resilient bond being mobilized between the granular medium and the geocell strips. Further, the interface friction depicted is found to be close to the wall friction angle adopted in the conventional design of retaining walls. This study helps to gather insights on the change in interface behavior under varying strain rates which becomes more essential in the case of varying rates of slope movements.