Research on fatigue accumulative damage of expansive soil in the alternation of wetting-drying environment

The shear strength of expansive soil has the obvious varying property with the changing of seasonal climatic. Based on Palmgrem-Miner linear accumulative damage theory, laboratory experiments on the strength of expansive soil combining with different wetting-drying cycle amplitudes were performed to discuss on the fatigue accumulative damage of expansive soil in the alternation of wetting-drying environment. The results show that: (I)The applying sequence of high (low) cycle amplitudes have significant effect upon the fatigue accumulative damage of expansive soil, and the strength attenuation of expansive soil is mainly controlled by the high circulate amplitude. (2) The Palmgrem-Miner linear accumulative damage criterion can basically reflect the fatigue accumulative damage process of expansive soil in the alternation wetting-drying environment, and the value of damage score "D" is close to 1 when the strength of expansive soil is stabled.