How does the absorption of water weaken unconsolidated slope materials?

unconsolidated materials are those that have not been packed and/ or pressed by any natural or human means, allowing small pockets of air going in and out of the material in question. The water absorption occurs by direct contact or by the condensation of moisture in the air, a process of oxidation occurs and oxygen is released into the atmosphere, leaving an empty space in the basic structure of the material in question. With time, the material degrade.