ABSTRACT
ABSTRACT: The main objective of this study was to determine vertical and horizontal displacements of geogrid samples during pullout tests. Laboratory pullout tests were performed on 1.5 m long 1 m wide geogrid specimens using the same type of soils at similar moisture content and density. Vertical and horizontal displacements of aggregates and geogrids during the pull tests were computed by utilizing digital image processing. Sensors mounted above and below the geogrid samples were used to monitor displacements during the tests. The digital image process was conducted through the 300 mm long and 150 mm plexiglas windows opened on the sides of the special designed large scale pullout test device. A feature of the testing program is that displacements of geogrid samples at each connection of longitudinal and transverse ribs were captured and computed through non-contact measurements. The vertical and horizontal displacements of the geogrid ribs (transverse and longitudinal) were found to be very small.
