A Study on the Mechanism of Internal Erosion Resistance to Soil Slope Instability

A study has been conducted to determine the mechanism of internal soil erosion resistance to soil slope instability. The common understanding is that higher probability of slopes failure normally occurred after prolonged heavy rainfall or antecedent rainfall. The infiltration of rainwater through the slope surface creates a path within the soil mass and/or flowing through crack surfaces which penetrate meters in depth. When the soil particles disperse into suspension and transported by water along the flowing movement, the removal particles will lead to internal erosion process. A laboratory study has been carried out to characterize the soil internal erosion resistance to slope instability due to rainwater infiltration and the effect of percentage of coarse to fine-grained soils composition. A pinhole test, crumb test and cylinder dispersion test were conducted to investigate the soil dispersibility characteristic. A randomly selected soil samples were extracted from soil slopes within UiTM, Shah Alam Campus. Samples were collected before and after rainfall. Initial result showed that the soil is prone to disperse near dry or at lower moisture content. Soil samples with higher composition of coarse-grained particles have higher dispersibility that lead to lower resistance to internal erosion