The maximum effective stress to which a clay deposit has been subjected during its entire formation and consolidation process, including any natural processes (e.g., sedimentation, compaction, uplift, ground water fluctuation) or man-made loading or unloading events (e.g., groundwater pumping, construction). Thus, the preconsolidation stress is the maximum value of all past and current effective stresses that have caused the clay to consolidate. The maximum past effective stress is generally determined experimentally by measurement of one-dimensional elastic and plastic deformation that occurs during consolidation, or one-dimensional stress-strain compression curves, or from known events, such as specific sea-level changes, groundwater table fluctuations, etc.
Syn., preconsolidation pressure
Cf., overconsolidation ratio