Plastic shakedown and creep limit of geocell-reinforced sand: experiments and modeling

In geotechnical engineering, geocells are widely utilized to reinforce soil, thereby enhancing its resistance to cyclic loads such as traffic, machinery vibrations, and wind or wave actions. While extensive research has been conducted on geocell-reinforced soils under static conditions, there remains a gap in understanding their deformation responses and shakedown behavior under long-term cyclic loading. This study explores this gap through a series of cyclic triaxial tests, investigating the effects of geocell material stiffness, confining pressure, and cyclic stress amplitude on the accumulated plastic deformation of geocell-reinforced soil. The efficacy of geocells in mitigating dynamic loads is assessed. Furthermore, the study analyzes the shakedown response of the reinforced soil and introduces an empirical model that identifies two critical stress thresholds: (1) the plastic shakedown limit stress, at which accumulated plastic strain stabilizes to a negligible level; and (2) the plastic creep limit stress, beyond which failure occurs due to the continual accumulation of plastic strain. The model is validated against the experimental results, providing a quantitative basis for assessing deformation behaviors in geocell-reinforced soil under cyclic loading.