A new reinforced materials as to strengthen the rib of conventional geogrid is proposed on the basis of horizontal-vertical reinforced soil

which has the effect of three-dimensional reinforcement. A series of pull-out tests of geogrid with strengthening ribs are performed to investigate the interface behavior between sand and strengthening rib geogrid inclusions in terms of different forms of reinforcements. 36 groups of pull-out test data are received by a large number of tests. The impacts of tooth height and tooth spacing of reinforcement on ultimate pull-out resistance are discussed. Test results show that the ultimate pull-out force of strengthening rib geogrid significantly larger than ordinary ones in the same normal stress. Ultimate pull-out resistance increased as the increase of the height of strengthening rib; while it decreased when increased the rib spacing under the same degree of rib height. From the test results

the coefficient of apparent pull-out friction is evaluated. The interaction mechanism between soil and geogrid with strengthening ribs is further analyzed. The influencing factors of ultimate pull-out resistance are discussed; and a new theoretical formula is proposed to determine the pull-out resistance. The comparison between theoretical values and experimental results is in good agreement.