The laboratory study of displacement rate effect in pullout test on the interaction between clay soil – geogrid

Reinforcement soil by geogrid is an effective way of increasing the strength of stretching and shearing in soil structures. Investigation and evaluation of the clay-geogrid interaction are prerequisites f or using geogrid in clay reinforcement. The present study has investigated the effect of vertical stress, loading speed variations, optimum moisture, saturation, and consolidation status in clay soil. The evaluation of interaction clay-geogrid was done by the pullout test. The results indicated that the geogrid pullout force at the interface depends on the vertical stress. Based on the results obtained, the pullout force was inversely related to the displacement rate, as with the increasing displacement rate, the geogrid pullout force decreased. The results of experiments illustrated that the geogrid pullout force were reduced in the saturation status, and the geogrid pullout force increased by consolidating clay soil. Moreover, The pull out geogrid from inside the clay was getting a hardening behavior.