Estimation of Water Level in Road Embankment by Transient Unsaturated Seepage Analysis

Estimation of water level for the persistent situation or prior to earthquake is crucial for evaluation of seismic performance of road embankments. Numerical modeling studies are conducted to investigate effects of several parameters on the water level in the embankment. Variation of rainfall intensity, size of embankment, thickness of permeable foundation, saturated permeability, and soil-water characteristic curve are considered. Parametric study reveals that height of embankment is proportional to convergent water level, time of water level rising onset, and convergent time. Rainfall intensity and permeability in the saturated condition are inversely proportional to these parameters. Considering the possible range of the road width and slope angle, relative thickness of the permeable foundation to the embankment height is the most influential factor on the water level in the embankment among the proportion parameters.