ESTIMATION OF FACTOR OF SAFETY FOR CLAYEY SOIL SLOPE UNDER DIFFERENT RAINFALL PATTERNS DUE TO THE EFFECT OF CLIMATE CHANGE

Abstract

One of the many negative effects of climate change on the global environment is land sliding as a result of precipitation. This is especially true in mountainous regions. This thesis presents a characterization of unsaturated soil to show that land sliding can occur on the surfaces of any slope. The clayey soil and sand-kaolin mixture soil slopes in Kazakhstan under extreme varied rainfall loadings are analyzed using simulation in this paper. Seepage and stability analyses are conducted using the SEEP/W and SLOPE/W modules of GeoStudio, depending on the selected slope heights and angles. The results demonstrate that as pore-water pressures rise during rainfall, so does the pushing force in the slope. This causes the soil's shear strength to weaken. Seepage research shows that in the middle of each slope, pore-water pressure had increased to over 80 kPa. Reduced suction and shear strength are the results. Results from the first stage show that the change in safety factor is smallest for the most gentle slope (27 degrees) and greatest for the steepest slope (30 meters) while the change in safety factor for the steepest slope (45 degrees) (9%) is nearly the same for all slope heights. The second stage of results showed that under advanced and cyclic rainfall loadings, FoS changed by around 6.5% for the 10 m height slope and almost 8.2% for 20 m at the gentlest slope with 27 degrees slope angle. The average decrease in FoS was 8.4% for a slope of 10 m and 12.5% for a slope of 20 m for continuous, delayed, and normally distributed rainfall. In other words, the loss of soil strength owing to a substantial volume of infiltration into the ground is confirmed by a general decrease in the safety factor across all simulation situations. The numerical studies also incorporated the sand-kaolin index properties obtained from experiments, which showed the same trend as the one for clayey loam. More preventative measures are needed to lessen the ecological and human toll of landslides.