Well-graded dense saturated sands have high shear strength because :

• A. Such sands have a better grade (superior type) of sand grains resulting in higher strength
• B. Such sands have lower water content, which increases shear strength
• C. Such sands have better interlocking of grains, higher inter-particle contacts and higher inter-particle frictional resistance resulting in higher strength.
• D. Presence of water in such sands induces capillary pressure generating higher inter-granular stresses, which generate apparent cohesion and hence higher shear strength.