Influence of Creep and Stress-Relaxation of Geosynthetic Reinforcement on Embankment Behaviour

The effects of viscous behaviour of geosynthetic reinforcement on both the short-term and long-term performance of basally reinforced embankments over inviscous soft foundations are investigated. The construction of embankments reinforced with both viscous reinforcement and inviscous reinforcement is numerically simulated to identify the magnitude of creep and stress-relaxation of reinforcement under both limit-state and working stress conditions and the consequent effects on the stability and deformations of the system. The effects of viscoelastic properties of four reinforcement products made of polyester, polypropylene, and polyethylene are examined. It is shown that the viscous behavior of geosynthetic reinforcement can decrease the short-term stability, and the creep of geosynthetic reinforcement can significantly magnify the long-term shear deformations of the foundation soil. The isochronous stiffness can reasonably represent the mobilized reinforcement stiffness at the end of construction. The mobilized reinforcement stiffness and force are examined and the design considerations are discussed.