Seepage and Stability of an Earth Dam under the Condition of Rainfall Infiltration

The effect of precipitation on the pore pressure of water in the soil and the stability of the slope of an earthen dam is investigated. The earth dam at Khac Khoan reservoir in Binh Phuoc province, Vietnam, was chosen as the case study. In doing so, the SEEP/W and SLOPE/W modules of the GEOSTUDIO software simulate the effects of rainfall on the changes of pore-water pressure of soil and the stability of the earth dam. Four distinct rainfall scenarios representing different intensities were used for the analyses to assess their impact on soil pore-water pressure and stability of the earth dam. The results show that rainfall induces notable changes in pore-water pressure and reduces slope stability, with the magnitude of these effects varying by scenario. Among the scenarios, the moderate-intensity, prolonged rainfall (Scenario 3) exerted the most significant destabilizing influence. Understanding how rainfall alters pore-water pressures and slope safety factors is crucial for evaluating stability under worst-case conditions and formulating appropriate operational and maintenance strategies.