ABSTRACT
Vertisoils are soils that experience change in volume and slickenside are one of the most important morphological features that reflect contraction and fissuring during the drying process, and swelling during wetting. Soils that vary in volume when inundated with water require extra care; regardless of the their use: agriculture, engineering or both. This paper aims at evaluating, through conventional and suction controlled oedometric tests, with various initial humidity and external applied stress, the changes in volume and expansion stress of the soil, due to change in water content in a vertisoil from Petrolândia-PE. The results show that the soil expansion, contraction or collapse, depend on the initial humidity and the external stress applied. The volume variation, in the course of time, due to change in soil humidity, could there be expansion, expansion jointly with collapse, and only collapse or contraction. The conclusion is that the volume changes due to water content variation are associated to the soil initial condition and the conditions that it has been submitted to.
