Effects of shear rate and material properties on shear strength of geosynthetic-soil interface

The strength parameters of the inferface between geosynthetics and soils are the key technical factors for the design of reinforced-soil engineering.The direct shear test and pullout test are widely used in characterizing interaction between geosynthetics and soils by experimental methods.The pullout tests of geotextile/geogrid buried in quartz sand and the direct shear test between geotextile/geogrid and sand were carried out;the attempt is made to explore the influence of shear rate and reinforcement material properties on the interface shear strength.The results indicate that the effect of shear rate on the interface direct shear strength could be ignored when the rate is not higher than a limited value(such as 7.0 mm/min).The interface strength is influenced by the types and characteristics of reinforcement material;the internal friction angles of interface between geotextile/bidirectional polypropylene geogrid and sand are similar to that of clear sand;but a lower internal friction angle value between fiberglass geogrid and sand was gotten as its lower elongation rate and the smaller grid sizes.