INDEX PROPERTIES, RELATIONSHIP & TESTS

By :- Shekhar Mehta

SOIL CONSISTS OF

SOLID PARTICLES WATER AIR

» For dry soil mass, the voids are filled with only air» For fully saturated soil mass, voids are completely filled

with water

THREE PHASES OF SOIL

ASSUMPTION FOR DRAWING PHASE DIAGRAM

» All particles of soil are having same size & density.

» Soil is partly dry & partly saturated.

» Moisture is uniformly distributed in the soil mass.

» Air in soil mass has no weight.

PHASE DIAGRAM OF SOIL

» Partly dry & partly saturated soil 3 phases (solid, water, air) 3 phase dia.

» Fully dry soil 2 phases (solid & air) 2 phase dia.

» Fully saturated soil 2 phases (solid & water) 2 phase dia.

THREE PHASES OF SOIL :-

THREE PHASE DIAGRAM OF SOIL

TWO PHASE DIAGRAM FOR FULLY DRY SOIL

TWO PHASE FOR FULLY SATURATED SOIL

Fundamental Formulas :-

» WATER CONTENT/MOISTURE CONTENT (W): w = Mw x 100 Ms

where, Mw = weight of water Ms = weight of dry soil

» BULK UNIT WEIGHT (Yb): ϒb = W

Vwhere, W = total weight of soil mass

V = vol. of soil mass

» DRY UNIT WEIGHT (ϒd):ϒd = Wd

Vwhere, Wd = total weight of soil solid

» SATURATED UNIT WEIGHT (ϒsat):ϒsat = Wsat

V» SUBMERGED UNIT WEIGHT (ϒsub):

ϒsub = (Wd)sub & V

ϒsub = ϒsat – ϒw

» UNIT WEIGHT OF SOLIDS (ϒS):

ϒS = WS VS

» SPECIFIC GRAVITY (G): G = WS WW OR ϒS ϒW

where, Ws = weight of given vol. of soil solid Ww = weight of equal vol. of distilled

water It has no unit.» VOID RATIO (e):

e = VV VS

where, Vv = vol. of voids Vs = vol. of solid

» POROSITY (n):n = Vv V

» DEGREE OF SATURATION (Sr):Sr = VW VV

For fully saturated soil, Sr = 1 & for fully dry soil, Sr = 0» AIR CONTENT (aC):

aC = Va VV = 1 – Sr

where, Va = vol. of air voids» PERCENTAGE AIR VOIDS (na):

na = Va V

» DENSITY INDEX/ RELATIVE INDEX (ID):ID = emax – e emax – emin

where, emax = void ratio in loosest state emin = void ratio in densest state e = natural void ratio of the deposit

» BULK DENSITY (ρb):ρb = M Vwhere, M = total mass

» DRY DENSITY (ρd):ρd = Md V

» SATURATED DENSITY (ρsat):ρsat = Msat V

» SUBMERGED DENSITY (ρsub):

ρsub = Msub V = ρsat – ρw

where, ρw = density of water= 1000 kg/ m3

FUNCTIONAL RELATIONSHIPS

» e = n OR n = e 1 – n 1 – e» e = w . G

Sr

» ϒb = (G + e . Sr)ϒw

1 + e» ϒd = ϒb

1 +w

INDEX PROPERTIES OF SOIL

» DEFINATION :-

˃ Those properties of soil which are used in the identification & classification of soils are called index properties.

» The various index properties of soils are :-

˃ Water content

˃ In-situ density

˃ Specific gravity

˃ Particle size

˃ Consistency

˃ Density Index

THANK YOU…..!!!!