Geosynthetic-reinforced retaining (GRR) walls have been increasingly used to support footings worldwide. Lateral displacements of wall facing and settlement of a footing on the wall under loading are key parameters to evaluate the performance of the GRR wall. This study evaluates the lateral displacements of the wall facing and the settlement of a loading plate on reduced-scale GRR wall models in the laboratory. The models were constructed in a test box under a plane strain condition in the geotech-nical testing laboratory at the University of Kansas. The wall models were constructed with modular con-crete block and wrapped-around facing. The dimension of each model test wall was 1.2 m long, 0.45 m wide, and 1.0 m high. Geogrid layers used as reinforcement in the models had a length of 0.7 m and verti-cal spacing of 0.2 m. A 0.2 m wide strip footing was placed on the top surface of each model wall with an offset distance of 0.2 m from the facing. A laser tape having an accuracy of 0.1 mm was used to measure the settlement of the loading plate and the lateral displacements of the wall facing. Two cameras were used for photogrammetry on different sides of the model to capture the wall distortion. Tape readings and photos were taken during the loading stage. Test results showed that the photogrammetry and laser tape
methods measur e d similar wall facing deformation s and footing settlements for both walls . The maximum lateral displacements measured by the laser tape and photogrammetry methods were at the depths of 0.38H (H is the wall height) and (0.25 to 0.30)H from the top of the walls with modular block and wrapped-around facing, respectively. The comparison also shows that the wall with wrapped-around facing had larger settlement and lateral wall facing displacements than the wall with modular block fac-ing.
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