Bearing force mobilisation in pull-out tests on geogrids

This paper presents a study on the mobilisation of bearing forces in geogrids subjected to pull-out solicitation. A theoretical model incorporating the effects of interference between grid bearing members on grid pull-out behaviour is presented and used for the interpretation of the results of large-scale pull-out tests on grids with varying geometrical and mechanical properties. The results obtained in this study show the influence of parameters such as free reinforcement length, test speed and interference between members on the pull-out response of geogrids. It is also shown that the load–displacement curve obtained in pull-out tests is not sufficient for an accurate investigation of soil–grid interaction and bearing force degradation mechanisms must be incorporated in the analysis of grid pull-out response if accurate predictions of pull-out strength and grid deformations are to be made.