An instrumented steep reinforced soil embankment at Åndalsnes, Norway

Abstract

The design and construction of an instrumented steep reinforced soil embankment built over a competent foundation is described. The embankment, which is intended to act as a snow avalanche barrier, was constructed from a uniformly graded medium sand and ‘Tensar’ SR2 geogrid was used as the primary reinforcement. Reinforcement strains were measured using ‘Bison’ strain coils and measurements were also made of stresses and lateral displacements occurring in the soil. The measured values of reinforcement strain are shown to be substantially less than those obtained from a limit equilibrium analysis of the embankment in which the mobilized friction angle is based on pressure cell measurements of vertical and horizontal total stress. This result is consistent with other published field trials and indicates an excessive conservatism in the limit equilibrium methods currently used for design.