Effect of fine grain contents on the unsaturated mechanical characteristics of embankment materials

In order to evaluate the safety of an embankment under unsaturated state against the infiltration of a heavy rain, the quantitative evaluation on the mechanical characteristics of embankment materials needs. In particular, this study concentrated on the fine grain content (under sieve #200) closely related to the decrement of shear strength due to the infiltration at a rainfall because the embankment is composed of soil materials involving fine and gravel grains. Thus, a series of the constant water content compression tests in this study are performed using a decomposed granite soil of the embankment. Through these results, the shear behavior on the fine grain contents from 10% to 40% is examined through the effect of the suction according to the degree of saturation. Here, the suction value is derived by the SSM (Suction stress-SWRC Method). It is expected that the effect of the fine grain contents on the unsaturated mechanical characteristics of embankment materials could be clarified through these results.