Soil behavior under load — recovery: A soil specimen changes shape and volume under an applied load but immediately and completely recovers both shape and volume upon unloading. This property is called:

Introduction / Context:
Engineering design relies on understanding whether soil deformations are recoverable or permanent. Terms like elasticity, plasticity, compressibility, and resilience have specific meanings and consequences for settlement prediction and cyclic loading response.

Given Data / Assumptions:

• Under load, the soil deforms (shape and volume change).
• Upon load removal, the soil recovers fully and immediately.
• No time-dependent drainage effects are implied in the description.

Concept / Approach:
Elasticity means strains are recoverable upon unloading and the stress–strain relation is reversible (within the elastic limit). Compressibility describes the propensity to decrease in volume under load but does not imply recovery. Resilience is the elastic energy stored per unit volume (area under the elastic portion of the curve) and is not itself the descriptive property for full recovery. Plasticity implies permanent deformation after unloading.

Step-by-Step Solution:

Verification / Alternative check:
In a typical unloading–reloading path on an elastic material, the curve retraces, confirming full recovery. Soils often show partial elasticity within small strains; the description here fits ideal elasticity.

Why Other Options Are Wrong:
They either describe different concepts (energy storage, permanent deformation) or are incomplete.

Common Pitfalls:
Confusing “elastic recovery” with “resilient modulus” used in pavement design; resilience is a parameter derived from elastic behavior, not the behavior itself.

Final Answer:
Elasticity of soils