A series of wetting tests on a weakly expansive soil

taken from Huaian

Jiangsu province

was performed to investigate the swelling and compression deformations. The influences of initial water content and initial dry density were studied under the applied vertical pressures from 25 kPa to 800 kPa. It is shown that the swelling deformation due to wetting is mainly affected by the initial dry density

and little affected by the initial water content. At the same initial water content

the swelling deformation increases with the initial dry density increasing. At the same initial dry density

the swelling deformation decreases little with the initial water content increasing. According to the points of intersection of the compression lines on unsaturated state and the saturated state lines with different initial densities

a state line is obtained. The state line is almost not affected by the initial water content. And it can judge whether the expansive soil will swell or compress due to wetting under different void ratios and vertical pressures. Finally

based on the results of wetting tests

a simple method for predicting the swelling deformation of expansive soils due to wetting is proposed.