Saturated shear strength is a key soil property and the reference of unsaturated shear strength,however,the variation of which is obvious. The mechanism of the variation of saturated strength was investigated. The direct shear tests under consolidated drained condition after the samples swelling to steady state were carried out for Jingmen expansive soil associated with six levels of compactness. The direct shear test results were compared with the results of triaxial compression tests. Comparative investig...