Based on three-dimensional (3D) reinforcing elements

a new reinforced material

geogrid reinforcement with vertical strengthening ribs in certain thickness is proposed

which has the effect of 3D reinforcement. By dyed sand observation method in pullout tests

the pullout mechanism of geogrid with strengthening ribs reinforced soil was analyzed. In pullout tests

a rigid soil wedge is formed by compacting

then moving together with reinforcement as a whole. A model of pullout resistance for geogrid with strengthening ribs was developed. In the proposed model

the lateral resistance of strengthening ribs is simplified to the lateral earth pressure

which was determined by active earth pressure and passive earth pressure of both sides based on the theory of limit equilibrium. The ultimate pullout resistance was calculated by the new theoretical model. It is shown that that the theoretical values are in good agreement with those of the pullout tests