Dynamic characteristics of saturated compacted loess under cyclic loads

Based on a series of dynamic triaxial tests on saturated compacted loess, the relationships among the excess pore water pressures, axial strains, effective stress paths, hysteresis loops and number of loading cycles are studied. Then, the effects of dynamic characteristics under different excitation amplitudes and dry densities are investigated. The results show that the excess pore water pressures and axial strains increase significantly at the beginning of triaxial tests. However, the effects of loading cycles on the excess pore water pressures and axial strains decrease gradually with the increase of loading cycles and become negligible when the loading cycles exceed a certain value. The effective stress paths move to left gradually with the increase of loading cycles, but the degrees of movement decrease gradually. The effective stress paths at the loading phase are essentially coincident with those at the unloading phase when the load cycles exceed a certain value. The hysteresis loops move to right gradually with the increase of loading cycles. With the increase of excitation amplitude, the excess pore water pressures and axial strains increase gradually. With the increase of dry density, the excess pore water pressures and axial strains decrease gradually.