Stability of Red-Clay Slopes Subjected to Different Durations of Rainfall

Open image in new window The influence of long duration rainfall on the stability and deformation characteristics of red‐clay slopes in China was evaluated using GeoStudio 2012. The 15 m tall modeled slope with a slope inclination of approximately 37° was subjected to rainfall at an intensity of 6.25 × 10−3 m/h for various durations. The durations examined in this study ranged between 1 day and 5 days. The pore water pressure and deformations resulting in the slope were evaluated using coupled and uncoupled analysis. Specifically, in the coupled analyses, the combined influence of seepage and deformation on the pore pressure, development of strains and the slope stability were examined. On the other hand, in the uncoupled analyses, only the influence of seepage on the pore pressure, strain development and factor of safety was considered. The results obtained suggest that the rate of pore pressure development was most significantly influenced when four days of rainfall was applied to the slope. The slope was found to settle following short duration rainfall events. However, the slope would swell during the long duration rainfall events. In these events, the greatest swelling was observed at the head of the slope. Similar to the pore pressure response, the factor of safety behaved hysterically with larger magnitudes noted in the coupled analysis in comparison to the uncoupled analysis.