Experimental study on interaction characteristics of geogrid-clay interface

Geogrid is a kind of geosynthetic material widely used in engineering. The interaction between geogrid and packed soil plays a decisive role in the stability of reinforced soil engineering. In this paper, the influence of normal stress, type of geogrid, water content and compactness of subgrade soil on the effect of reinforcement was studied, and the influence degree of each factor was analyzed by grey correlation method. The results show that under the same conditions, both the friction-like coefficient and the maximum shear stress of reinforced soil with bi-directional geogrid are significantly higher than those with unidirectional geogrid. With the increase of normal stress, the maximum shear stress between reinforcement and soil increases, while the friction coefficient decreases slightly with the increase of normal stress. The higher the compactness of the filler, the higher the friction coefficient between the reinforcement and soil. The higher the moisture content, the smaller the friction coefficient between the soil and the reinforcement. According to the grey correlation method, the influence of each factor from large to small is type of geogrid > degree of compaction > water content > normal stress. Therefore, it is suggested that bidirectional grid should be used in engineering and reduce the water content appropriately, which will make the geogrid reinforcement effect reach the best. An elastic-exponential hardening model was proposed to describe and analyze the interface behavior of bidirectional geogrid reinforced clay, and the results can be used as a guide for clay stiffening engineering.