Question

Based on drained triaxial shear tests on sands and clays, the representative variations of volumetric strain (\( \Delta V / V \)) with the shear strain (\( \gamma \)) is shown in the figure. 

Choose the CORRECT option regarding the representative behaviour exhibited by Curve P and Curve Q.

• A. Curve P represents dense sand and overconsolidated clay, while Curve Q represents loose sand and normally consolidated clay.
• B. Curve P represents dense sand and normally consolidated clay, while Curve Q represents loose sand and overconsolidated clay.
• C. Curve P represents loose sand and overconsolidated clay, while Curve Q represents dense sand and normally consolidated clay.
• D. Curve P represents loose sand and normally consolidated clay, while Curve Q represents dense sand and overconsolidated clay.

Hint:

In soil mechanics, dense sand exhibits contraction under shear, while loose sand exhibits expansion. Overconsolidated clay has higher shear strength compared to normally consolidated clay.

Answer 1

The Correct Option is A

In drained triaxial shear tests, the variations of volumetric strain with shear strain depend on the material's state (loose or dense sand, overconsolidated or normally consolidated clay).
- Curve P represents a material that exhibits dense behavior for sand and overconsolidated behavior for clay. Dense sand contracts (compression) under shear, and overconsolidated clay has a higher peak shear strength.
- Curve Q, on the other hand, represents a material with loose sand and normally consolidated clay. Loose sand tends to expand (dilatancy) under shear, and normally consolidated clay exhibits lower peak shear strength compared to overconsolidated clay.
Thus, Curve P corresponds to dense sand and overconsolidated clay, and Curve Q corresponds to loose sand and normally consolidated clay. Final Answer: Curve P represents dense sand and overconsolidated clay, while Curve Q represents loose sand and normally consolidated clay.