What is preconsolidation pressure?

Preconsolidation pressure is defined as the maximum pressure that soil has experienced prior to a new loading condition. This concept is crucial in geotechnical engineering, particularly when assessing the consolidation properties of saturated soils, which typically undergo volume change when subjected to loading.

Understanding preconsolidation pressure helps engineers predict how soils will behave under new loads. If a new load exceeds this preconsolidation pressure, the soil is expected to consolidate, resulting in settlement. This understanding is vital for designing foundations, retaining structures, and other civil engineering applications where soil stability is critical.

In contrast, other options do not accurately reflect the meaning of preconsolidation pressure. The minimum pressure required for soil compaction relates more to the initial compaction process rather than historical loading conditions. The compressive strength of the soil focuses on the material's resistance to failure under stress and is not indicative of previous pressure levels. The pressure at which soil begins to exhibit elastic behavior pertains to the initial loading phase and the material's responses rather than the historical maximum indicative of preconsolidation conditions. Thus, option B accurately captures the essence of preconsolidation pressure in soil mechanics.