Drained and Undrained Conditions

Drained and undrained conditions describe how soil responds to loads or forces. In drained conditions, water within the soil can flow out freely, allowing the soil to gradually adjust and settle. This process is slow, and long-term stability can be assessed accurately. In undrained conditions, water cannot escape quickly, causing the soil to behave as if it's temporarily trapped, leading to immediate, often more significant, changes in strength and stability. This situation occurs during rapid loads like earthquakes or quick construction. Understanding these conditions helps engineers predict how soil will behave under different scenarios and design safe foundations.