Tiivistysvaihe

Tiivistysvaihe refers to the consolidation phase in soil mechanics. It describes the process by which a saturated, low-permeability soil, such as clay or silt, loses volume due to the expulsion of pore water under applied load. This expulsion of water reduces the pore pressure, which in turn increases the effective stress within the soil. The increase in effective stress leads to a decrease in void ratio and thus a reduction in the overall volume of the soil.

The rate of consolidation is governed by the permeability of the soil and the drainage path available for the water to escape. Soils with lower permeability consolidate more slowly. Consolidation can occur over long periods, from days to years, depending on the soil conditions and the magnitude of the applied load. This phenomenon is a critical consideration in geotechnical engineering, particularly when designing foundations, embankments, and other structures built on or with fine-grained soils. Unforeseen consolidation can lead to excessive settlement, potentially compromising the structural integrity of the project.

Understanding and predicting the extent and rate of tiivistysvaihe is essential for accurate settlement analysis and the design of appropriate mitigation measures. Laboratory tests, such as the oedometer test, are commonly used to determine the consolidation characteristics of a soil, including its compressibility and coefficient of consolidation, which are vital parameters for these calculations.