Long-term variations of force and strain in a steep geogrid-reinforced soil slope

Instrumentation was used to measure soil temperature and, independently, the force and strain in a steep geogrid-reinforced soil slope. The monitoring period extends to 10 years after construction. A nonlinear increase of force occurs with time that is described by a hyperbolic representation. The elapsed time to achieve force equilibrium was approximately 2.5 x 10(4) hours (approximately three years). The time-dependent increase of reinforcement force is attributed to deformation of the structure resulting from creep of the backfill sand. Strain in the reinforcement exhibits a complex variation with time. The long-term variation of strain is attributed primarily to: (i) the nonlinear increase of force; and (ii) creep of the geogrid reinforcement. Seasonal temperature fluctuations in the backfill sand may induce additional variations in strain.