Dams MCQ with answer and solution

Concept

Core material of a zoned earth dam

Step-by-step solution

1. The core of a zoned embankment dam must be impervious but also stable and not crack. 2. Clay mixed with fine sand gives low permeability with good workability and reduced shrinkage cracking.

Explanation

A central core is built of the most impervious material available. A well-graded clayey soil mixed with some sand or silt gives low permeability, adequate strength and less cracking than pure clay.

Shortcut

Core = impervious but stable (clay + some sand). Shell = pervious (sand/gravel).

Common mistake

Choosing pure clay for being the most impervious.