Alireza beyranvand - Assistant Professor Department of Civil Engineering faculty of construction and architecture,Techtical and Vocational University (TVU),Tehran,Iran

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.

Clay soil, Geogrid, Interaction, Pullout test, Displacement rate line