Soil consolidation primarily occurs due to the expulsion of water from the soil pores under the influence of applied stress, resulting in a reduction in soil volume.

Terzaghi's Consolidation Equation, also known as the one-dimensional consolidation equation, describes the rate of settlement of a soil layer under a constant load.

The coefficient of consolidation (Cv) represents the rate at which water is expelled from the soil pores under a consolidation load, indicating the soil's permeability.

The time required for 50% consolidation (t50) is related to the coefficient of consolidation (Cv) and the square of the drainage path length (H) by the equation t50 = 0.197 * H^2 / Cv.

A preloading surcharge is applied to accelerate the consolidation process by increasing the effective stress on the soil, thereby expediting the expulsion of water from the soil pores.

Sand, due to its larger grain size and higher permeability, exhibits a higher consolidation rate compared to clay and silt, which have smaller grain sizes and lower permeability.

The magnitude of settlement in soil consolidation is primarily influenced by the soil's compressibility, which represents its ability to deform under applied stress.

Primary consolidation occurs rapidly due to the expulsion of water, while secondary consolidation occurs slowly due to the rearrangement of soil particles. Primary consolidation is influenced by soil permeability, while secondary consolidation is influenced by soil compressibility.

The coefficient of volume change (mv) represents the change in soil volume per unit change in effective stress. It is used to calculate the settlement of a soil layer and is related to the soil's compressibility.

Terzaghi's Theory assumes that the soil is fully saturated and behaves as a linear elastic material, making it applicable to a wide range of soil conditions.

The time factor (T) represents the ratio of the elapsed time to the time required for 50% consolidation. It is used to determine the degree of consolidation and is related to the coefficient of consolidation (Cv).

Sand drains are installed in soil to increase the rate of consolidation by providing a preferential path for water to escape, thereby accelerating the settlement process.

Biot's Theory considers the effects of creep and secondary consolidation by incorporating viscoelastic behavior into the soil model, providing a more comprehensive representation of soil consolidation.

Soil layering can lead to differential settlement, affect the rate of consolidation, and result in the formation of perched water tables, making it an important factor to consider in consolidation analysis.