Abstract: Field experiment on the embankment at bridge approach reinforced by triaxial geogrid is carried out in Changzhi to Pingshun expressway. The earth pressures of the embankment fill below and above the triaxial geogrid and the deformations of the triaxial geogrid measured in cases of its attachment to or not to the abutment. The effective length and the effect of the triaxial geogrid reinforcement in the embankment of bridge approach are investigated. In addition, the differential settlements at the bridge approach of and the tensile forces of the geogrid are analyzed through numerical simulations. The results show that the earth pressures and the settlements can be reduced by the triaxial geogrid reinforcement in the embankment in a certain extent, and the effect of the triaxial geogrid reinforcement is extend to nearly 6 m from the abutment. The tensile force of the triaxial geogrid can be increased and the settlement can be reduced with the triaxial geogrid attached to the abutment. While the effect of reinforcement without attachment is not obvious. The tensile stiffness of the geogrid and the cohesion of embankment fill have great effect on the tensile force and the settlement of the embankment. Thus the geogrid with appropriate tensile stiffness the embankment fill with suitable cohesion should be employed in practice.