Abstract: The interaction between geogrid and soil explains the reinforcement mechanism. Geogrid ribs play a very important role. By middle-scale indoor pull-out test, we analyzed the forces acting on one-way geogrids and two-way geogrid ribs. Results revealed that ribs contributed over 30% of the friction during the pull-out. The friction coefficient and cohesion of interface reduced remarkably in the absence of ribs. Part of the pull-out force measured during the test was provided by geogrid ribs, so the calculation result was smaller than the actual situation.

Key words: geogrid, interface between reinforcement and soil, pull-out test, transverse ribs