Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
Gravel and sand is a
Cohesive coarse grained soil
Cohesive fine grained soil
non-cohesive coarse grained soil
non-cohesive fine grained soil
non-cohesive coarse grained soil
Gravel and sand are classified as coarse-grained soils because their particle sizes are greater than 0.075 mm, allowing them to be retained on a standard No. 200 sieve. They are non-cohesive because they lack clay minerals and do not exhibit significant inter-particle attraction forces, relying instead on internal friction for shear strength.
Gravel and sand are classified as coarse-grained soils because their particle sizes are greater than 0.075 mm, allowing them to be retained on a standard No. 200 sieve. They are non-cohesive because they lack clay minerals and do not exhibit significant inter-particle attraction forces, relying instead on internal friction for shear strength.
╧Д=╧Гtan(╧Х) тАФ Coulomb's law for shear strength of non-cohesive soils, where ╧Г is normal stress and ╧Х is the angle of internal friction.
D50тАЛ тАФ Particle diameter corresponding to 50% passing, often used to characterize sand/gravel grading.
The classification is governed by particle size distribution. Coarse-grained soils have >50% of particles by mass larger than the 0.075 mm sieve size. Unlike fine-grained soils (silts and clays), which exhibit cohesion due to electrochemical surface forces, coarse-grained soils exhibit 'cohesionless' behavior where the shear strength is expressed as ╧Д=╧Гtan(╧Х), where ╧Х is the angle of internal friction.
Coarse-grained soils include gravel (G) and sand (S) based on the Unified Soil Classification System (USCS).
Non-cohesive soils derive their strength primarily from friction and interlocking.
These soils possess high permeability and high shear strength when compacted.
Clay and silt are termed fine-grained and exhibit cohesive properties.
Excellent drainage properties.
High bearing capacity when well-graded and compacted.
Susceptible to liquefaction during seismic activity.
Difficult to stabilize without binders.
Base and sub-base materials in pavement construction.
Foundation beds for shallow foundations.
Drainage layers behind retaining walls.
In the Indian Standard Classification System (ISCS), coarse-grained soils have >50% of material retained on the 75-micron sieve.
Option A and B are incorrect because they categorize these materials as 'cohesive,' which is a property reserved for clays containing significant electrochemical bonding.
C is correct тАФ Gravel and sand are characterized as coarse-grained and non-cohesive because they lack the plastic clay minerals necessary for cohesive behavior.
Always remember: Cohesion is a property of fine-grained soils (clay), while friction is the dominant strength component for coarse-grained soils (sand/gravel).