The relationship between strength and water content of expansive soil

In this paper, the strength theory of unsaturated soil is utilized to analyze the strength of expansive soil and its factors influenced. The consolidated undrained shear test is made by using soil sample of different water content. The relationship between the strength of expansive soil and its water content is studied. The results show that the peak value strength and stable state strength of the expansive soil are strongly affected by its water content. With increasing the water content, the strength become apparently lower. The change of coherent force is more than the change of friction angle when the water content of expansive soil is changed.