Experimental research on shearing resistance property of sand-geogrid interface under cyclic load

A series of direct shear tests were performed using self-developed large-scale interface shear apparatus to investigate the shearing resistance properties of sand-geogrid interface and compare the experimental results under normal cyclic load with those under static load. The test results demonstrate that the development trend of shear stress-displacement curves under cyclic load are similar to those under static load; but the shear curves under cyclic load show cyclic development characteristics; the relationships between the maximal shear stress of peak value and normal stress, and the maximal shear stress of trough value and normal stress both conform basically to Mohr-Coulomb rule; the maximal shear strength under cyclic load decreases with the increasing of frequency, but increases with amplitude increasing; the shear strength under cyclic load fluctuates with shear displacement, but is always in between the upper and lower boundaries defined by the shear stress under corresponding static normal stresses; the specific quantitative relationship among these related physical variables needs further researches.