Influence of cyclic tensile loading on pullout resistance of geogrids embedded in a compacted granular soil

This paper deals with some results of a wide experimental research carried out in order to study factors affecting cyclic and post-cyclic pullout behaviour of different geogrids embedded in a granular soil. The new test procedure developed (multistage pullout test) and the relative results are described. In particular, test results obtained using the constant rate of displacement (CRD) and the multistage pullout tests highlighted the influence of the different factors involved in the research (cyclic load amplitude and frequency, vertical confining stress, geogrid tensile stiffness and structure) both on the peak pullout resistance and on the peak apparent coefficient of friction mobilized at the interface.