What is meant by the term 'soil consolidation'?

Soil consolidation refers to the process where soil volume is reduced as a result of the expulsion of pore water from its voids. This phenomenon typically occurs under the influence of sustained loads applied to the soil, leading to increased effective stress on the soil particles. As the load is applied, the water between the soil particles is pushed out, which causes the soil to settle and its volume to decrease.

This process is significant in geotechnical engineering because it affects the stability and settlement of structures built on or within soil. Proper understanding of soil consolidation is essential for predicting how soil will behave over time under loading conditions, which is critical for designing foundations and other civil engineering structures. The other options do not accurately represent the definition of consolidation; for instance, adding water to soil would increase its volume rather than reduce it, and chemical stabilization is unrelated to the physical processes of consolidation.