Experimental study on the behaviors of sand-gravel composites liquefaction

By use of medium scale dynamic triaxial apparatus(phi 200x500mm) the development of axial strain and pore water pressure of sand-gravel composites are studied in cyclic loading. Adopting same relative density, a series of substituted material specimens gained by eliminating the oversized (> 5mm) gravel particles are studied. The results show that with isotropic consolidation, the development of excess pore water pressure and axial strain in sand-gravel composites differs from that in substituted material. A series of undrained cyclic triaxial tests were performed on sand-gravel composites specimens with relative density of 50%, 55%, and 60%. Test results showed that the increase of relative density may delay the development of pore pressure of sand-gravel composites.