Large-scale shaking table tests on seismic behavior of deposit slopes with varying moisture content

Dynamic response of deposit slopes is complex with multiple influencing factors. The large-scale dynamic triaxial tests reveal that moisture content affects greatly on dynamic shear modulus and damping ratio of deposit. As such, two groups of large-scale shaking table model with scale of 1:12 of deposit slopes are tested with different moisture contents. Comparisons of acceleration and crest displacements distribution of 2 deposit slopes under multiple sequential ground motions show that, in either 2 models with different moisture conditions, the first order natural frequencies of model slopes decrease with the increasing loading sequence, while the corresponding damping ratios increase with its increasing. The slope model with 6.6% moisture content has larger numbers of first order natural frequency, damping ratio and peak ground acceleration (PGA) amplification coefficients than the numbers for model with 0.7% moisture content. The Fourier spectrum of slope crest accelerations of these 2 models are similar. The amplification effect of crest acceleration enhances evidently when the predominant frequencies of input seismic waves approach to the first order natural frequencies of the deposit slope. the input frequencies of seismic waves approaching the first order natural frequency from the lower frequencies side of slope amplifies PGA significantly than from the higher frequencies side. The permanent displacements of deposit slope crest with 6.6% moisture content are larger than that of 0.7% moisture content slope. In addition, the crest permanent displacements with higher moisture content are more sensitive to the spectra characteristics of input seismic waves.