Direct shear tests were performed over a soil samples retrieved from a south-eastern of Antioquia of the EIA at the Palmas campus. The soil under study is a residual soil from amphibolite, the sample depth was 2.50 meters. It was determine the change in cohesion and internal friction angle by increase the saturation immersing the samples for different times in a mixture with a concentration of 34.50 ml of powder detergent per 1 liter of water.