Symbol used for Cobble component (IS-1498-1970) is

Question

Question

This question was previously asked in

JKSSB JE Civil Jal Shakti 6 Dec 2022 Official Paper (Shift 1)

Answer 1

Concept:

As per IS-1498-1970, Table 1(Clauses 3.2.2)

Basic Soil Components:

Soil	Soil Component	Symbol	Particle Size Range and Description
Coarse-grained component	Boulder	None	Round to angular, bulky, hard, rock particle; average diameter more than 300 mm.
Coarse-grained component	Cobble	None	Round to angular, bulky, hard, rock particle; average diameter smaller than 300 mm but retained on 80-mm IS Sieve.
Coarse-grained component	Gravel	G	Round to angular, bulky, hard, rock particle; passing 80-mm IS Sieve but retained on 4.75-mm IS Sieve. Coarse: 80-mm to 20-mm IS Sieve Fine: 20-mm to 4.75-mm IS Sieve
Coarse-grained component	Sand	S	Round to angular, bulky, hard, rock particle; passing 4.75-mm IS Sieve but retained on 75-micron IS SIeve. Coarse: 4.75-mm to 2.0-mm IS Sieve Medium: 2.0-mm to 425-micron IS Sieve Fine: 425-micron to 75-micron IS Sieve
Fine-grained component	Silt	M	Particles smaller than 75-micron IS Sieve; are identified by behavior, that is, slightly plastic or non-plastic regardless of moisture, and exhibit little or no strength when air dried.
Fine-grained component	Clay	C	Particles smaller than 75-micron IS Sieve; are identified by behavior, that is, it can be made to exhibit plastic properties within a certain range of moisture and exhibits considerable strength when air dried.
Fine-grained component	Organic Matter	O	Organic matter in various sizes and stages of decomposition.