4.2 TOTAL STRESS, PORE WATER PRESSURE AND EFFECTIVE STRESS: UNDERSTANDING SOIL BEHAVIOR SIMPLIFIED
Understanding how soils behave under loads is critical in geotechnical engineering . Engineers design foundations, retaining walls, and embankments based on how soil responds to stress. Water may influence the nature of the mineral surface chemically and consequently affect the bonding forces between adjacent soil grain. This kind of interaction between the soil solid and water is called chemical interaction. The other kind of interaction is a physical interaction between solid and water. Volume of the soil skeleton as a whole can change due to rearrangement of soil particles into new position mainly by rolling and sliding due to forces acting between the particles This physical interaction is studied when we study the effective stress concept: given by Terzaghi. The effective stress concept applies to a fully saturated soil and relates three key concepts to help us grasp soil behaviour: Total Stress, Neutral Stress ( Pore Wa...