EFFECT OF UNSATURATED SEEPAGE ON SLOPE STABILITY UNDER RAINFALL

摘要

A fractal model can forecast the hydrological characteristics of unsaturated soil. This study investigates the process of one-dimensional unsaturated soil seepage, combined with analysis of pore airflow. According to the fractal approach to unsaturated shear strength, a new formulation was derived to define the critical depth for slope failure under rainfall. The factors, the fractal dimension, and air-entry value were determined to control the stability of unsaturated soil slopes under rainfall. The saturated coefficient of hydraulic conductivity and rainfall intensity has a greater effect on the instability of unsaturated soil slopes. For the case where the rainfall intensity is much larger than the saturated coefficient of hydraulic conductivity, the pore-air pressure in the infiltration process affects the soil suction pattern.