Features and stability analysis of rainfall-induced colluvial landslides

The colluvial landslide is a kind of basic type of landslides; and its matter component and structure are different from other type landslides. The slope instability of colluvial landslide mostly is induced by rainfall or change of groundwater level; and groundwater plays a fateful role in the slope instability, therefore, the seepage action should be considered in the landslide stability analysis. The growth environment and characteristic of a colluvial landslide is analyzed systematically. Based on total stress method and effective stress method, a transfer coefficient method with considering seepage forces for landslide stability analysis is established. Adopting effective stress method to calculate the landslide stability factor, both the buoyancy force of groundwater to soil and seepage force should be considered; and adopting effective stress method to calculate the landslide stability factor, only seepage force should be considered. At last, an example is thoroughly analyzed; and the result shows that the transfer coefficient method with considering seepage forces for landslide stability analysis is reliable.