Use of geosynthetic basal reinforcement to limit lateral spreading of embankments subjected to earthquake loadings

Historically, little attention was given to the seismic performance of embankments because they were not considered critical structures. Of recent times, their seismic stability has gained in importance be-cause of the need to ensure serviceable infrastructure immediately following earthquake events. The major form of embankment distress during earthquakes is lateral spreading which occurs during liquefaction of the foundation. The paper provides a method where geosynthetic basal reinforcement is used to limit the lateral spreading of embankments during and following earthquake loadings thereby maintaining serviceability. The method uses a pseudo-static limit equilibrium approach to determine the tensile load generated in the basal re-inforcement. By limiting the horizontal displacement of the embankment toe to meet serviceability require-ments the maximum allowable basal reinforcement strain is established. The combination of reinforcement tensile load and maximum allowable strain enables a suitable geosynthetic reinforcement to be defined that accounts for tensile strength, strain, design life, as well as installation and durability effects.