Research on bearing capacity of cast-in-place piles in unsaturated to saturated loess

Based on a great number of laboratory tests on soils and loading tests on cast-in-place piles in the loess region,the rules of the shear strength decreasing with the increasing of moisture content of the loess,the development and variation of skin resistance and the additional settlement deformation of piles with saturation of unsaturated loess were found.The emperical formulas of the skin resistance and bearing capacity of piles were set up for the loess.