What does shear strength depend on in relation to soil properties?

Shear strength of soil is a crucial parameter in geotechnical engineering, and it fundamentally depends on the internal resistance of the soil particles to sliding past each other. Cohesion is a key factor that contributes to this internal resistance, as it represents the attractive forces between soil particles. It is particularly significant in saturated or fine-grained soils where water saturation influences the effective stress and enhances the bonding between particles.

In the context of shear strength, cohesion provides the strength necessary to maintain stability under loading conditions. It works alongside internal friction, which is influenced by the density and granularity of the soil, but cohesion itself is the primary contributor when considering the strength in fine-grained soils, such as clays. Therefore, understanding cohesion and how it interacts with other soil properties is essential for accurate assessments of shear strength in various geotechnical applications.