What can result from excessive pore water pressure in soil during loading?

Excessive pore water pressure in soil during loading can lead to potential soil failure. When loads are applied to saturated soils, the interstitial water pressure increases, reducing the effective stress within the soil matrix. Effective stress is a key factor that contributes to soil strength. As pore water pressure rises, the soil particles are pushed apart, which decreases friction and cohesion between them, ultimately lowering the overall strength of the soil structure.

In conditions where pore water pressure is significantly high, it may lead to a scenario known as liquefaction, especially in saturated granular soils during sudden or dynamic loading conditions, such as earthquakes. This loss of strength can result in instability, causing the soil to fail under the applied load.

This understanding highlights the critical relationship between water pressures and soil stability, emphasizing the importance of monitoring and managing pore water pressures in geotechnical engineering and construction.