The correlation of soil liquid limit and plasticity index for predicting soil susceptibility: A case study on landslides area in South Sulawesi

Abstract

This research aims to analyze a characteristic of liquid limit and plasticity index of soil to predict soil susceptibility on landslides area in four districts of South Sulawesi which has a high intensity of landslides event. Soil sampling was done in sixteen soil profile on A, B, and C horizon. The experiment used a split-split plot design with three replications. The ASTM-D method was used for calculating the liquid limit, plasticity limit and index plasticity. The average value of liquid limit in landslides area was 67.91%, plasticity limit was 52.22%, and index plasticity was 16.23%. Statistical test showed a correlation between landslides event with soil characteristic on each horizon with significant at P < 0.05. The least significant difference test showed the correlation between landslides event with soil characteristic on A and B horizon, and not significant on the C horizon. The Soil with 67.91% of liquid limit value and 16.22% of index plasticity classified as silt of high plasticity with low cohesiveness, and it is very susceptible to trigger a landslide.