Experimental tests on relationship between suction and water content of remolded lateritic clay in Guangxi under high suction

The suction has important influence on the properties of unsaturated soil. To explore the relationship between suction and water content of unsaturated lateritic clay can serve the local economy effectively. The soil-water characteristic curves (SWCC) of unsaturated lateritic clay with different initial water contents in Guangxi are measured by using the vapor equilibrium technique under high suction rang of 3~368 MPa. The results show that the water content or the degree of saturation decreases with the increasing control suction and increases with the decreasing control suction. When the value of control suction is less than 21.82 MPa, the drying or wetting rate of soils is getting down. The hysteresis phenomenon between the drying and wetting curves is more obvious when the control suction is smaller. The relation curves between suction and water content of soil samples with different initial water contents are coincident, but those between suction and saturation are not coincident. The main cause is that the variation in water content is not proportionate to the soil swelling or shrinkage deformation, and the relation curve between suction and void ratio confirms this further. Accordingly we should choose the right coordinate variables for SWCC of lateritic clay according to the actual situation. The results provide basic data for the analysis of soil water holding characteristics in local slope, which makes a contribution to the disaster prevention and reduction of the engineering practice in this area.