Bearing mechanism of steel grid reinforcement in pull-out test

A series of pull-out tests on a composite of welded steel grid reinforcement and granular soil is carried out under different normal pressures to investigate the bearing mechanism of transverse members. This steel grid reinforcement is different from polymer geogrid reinforcement because the longitudinal member of steel grid is less extensible than that of polymer geogrid. Therefore, the bearing resistance mobilized by each transverse member is found to be approximately equal. A general expression representing a relationship between ultimate bearing resistance and normal pressure is developed, which is based on the Prandtl’s theory of bearing resistance failure mechanism. This general expression can easily be reduced to the available bearing resistance failure mechanisms. The proposed relationship between bearing resistance and normal pressure can be seen to reasonably represent many available pull-out test results.