Physical Model Tests of Half-Scale Geosynthetic Reinforced Soil Bridge Abutments. I: Static Loading

This paper presents experimental results from physical model tests on four half-scale geosynthetic reinforced soil (GRS) bridge abutment specimens constructed using well-graded angular backfill sand, modular facing blocks, and uniaxial geogrid reinforcement to investigate the effects of applied surcharge stress, reinforcement vertical spacing, and reinforcement tensile stiffness for working stress, static loading conditions. Facing displacements increased for the upper section of the walls after the application of surcharge stress and were greater for larger reinforcement vertical spacing and reduced reinforcement tensile stiffness. Bridge seat settlements were proportional to the applied surcharge stress, strongly affected by larger reinforcement vertical spacing, and only slightly affected by reduced reinforcement tensile stiffness. Measured vertical and lateral soil stresses generally were lower than calculated values for static loading conditions. The maximum tensile strain in each reinforcement layer occurred near the facing block connection for lower layers and under the bridge seat for higher layers. A companion paper presents experimental results for the same GRS bridge abutment specimens under dynamic loading conditions.