scope:

In this study, air pressure behavior within an earth structure was investigated through a full-scale embankment test. The road embankment (2 m height) was constructed on low-permeability soil and measurement devices (tensiometers, air pressure meters, and soil moisture meters) were installed. The embankment was exposed to natural conditions, such as rainfall and evaporation, and vehicle weight was applied. Characteristic behaviors of water and air pressure were observed throughout the 1-year monitoring period. Water pressure increased under rainfall and kept decreasing due to evaporation without rainfall. The infiltrated rainwater flowed toward the slope toe. Consequently, water pressure at top of the slope increased due to rainfall and decreased soon after rainfall stopped; while pressure at the slope toe started decreasing after a period of time. Conversely, air pressure increased under only heavy rain. Moreover, it decreased to a point lower than atmospheric pressure following the heavy rain and recovered after a brief interval.