Consolidation MCQ with answer and solution

Concept

The coefficient of consolidation c_v controls how fast consolidation settlement takes place.

Formula

T_v = c_v t / d²; c_v = k / (m_v γ_w)

Step-by-step solution

1. Terzaghi's theory uses the time factor T_v = c_v t / d². 2. For a given degree of consolidation, t = T_v d² / c_v. 3. So c_v gives the time needed for settlement. 4. Total settlement uses C_c or m_v, not c_v. 5. Answer: time rate of settlement, option D.

Explanation

The coefficient of consolidation c_v tells how fast water leaves the clay under load. It is used to find the time for a given percentage of settlement. The amount of settlement is found from the compression index or m_v.

Why the other options are wrong

A: Stress in soil is found from Boussinesq or Westergaard theory. B: Total settlement uses C_c or m_v. C: OCR uses preconsolidation pressure and present effective stress.

Shortcut

c_v gives HOW FAST; C_c or m_v gives HOW MUCH.

Common mistake

Thinking c_v gives the total settlement amount.