the, consolidation
The compression of a soil takes place chiefly as a function of a decrease of the volume of the voids. If the voids of a soil are fully filled with water, some soil compression results after the outflow of excess water from the voids. Gradual compression or increase in the tensity of a soil under these conditions caused by natural action of forces of gravity such as the weight of the soil itself or the weight of the structures erected on it, is called the consolidation of soil. If a saturated soil is pervious (such as clean sand) its consolidation under newly applied static loads will be quick, as the excess water easily flows out of the voids. But if the saturated soil is a clay with low permeability, its consolidation wall be very slow as the excess water will take some time to penetrate to the pervious layers of the clay. The decrease of the volume of the voids of a fully saturated clay is equal to the amount of the water squeezed out. As a result of this process, the solid grains of the soil skeleton come into closer contact with each other and so take up some of the newly applied load. The stresses of the soil skeleton are called effective stresses.
