Abstract: Considering that the measured interface properties between soils and geosynthetics are prone to being influenced by experimental apparatus, authors applied large-scale laminated shear apparatus to conduct the shear tests on interface between geotextile and sand instead of common direct shear apparatus. The comparative analysis of the results from laminated shear tests shows that the displacements of laminated rings of sand with geotextile are smaller than those in shear tests of sand. The horizontal displacement of each ring is closely related to the dilatancy of sand. The geotextile limits the movement of soil particles in lower shear box and reduces the dilatancy ratio of sand at the peak interface shear strength. It can be inferred from the experimental results that the shear band caused by the interface shear between geotextile and soil is much narrower than its influencing range. The effect of geotextile in the interface shear test cannot be reflected only by the size of shear band, but also by the shielding function of geotextile from shear and its influence on the development of shear band in soil.

Key words: geosynthetics, laminated shear test, reinforcement influencing range, shear band, dilatancy