Degree of saturation

Degree of saturation mainly denoted by Sr.

Specific gravity of soil

Specific gravity of soil may defined as the ratio of unit weight of soil to the unit weight of water. I hope this video may evident about the concept ofspecific gravity of soil.

Soil aggregate property

# Relative density :
Relative density is the one of the major property of soil aggregate. In this property it describes about the relative compactness of soil as very loose, loose, medium, dense and very dense. Mathematically, Relative density is given by: 

Hydraulics of laminar flow

For laminar flow, poisseulie's derived an expression for discharge through a round capillary tube as :
             K = c x d^2  x (e^3/1+e) x Yw/ų
This is the equation to determine the value of permeability.

Soil water, Capillarity, and permeability

# Held water
The water held by the forces that is other than the force of gravity is called held water.
# Held water is also classified as :
1. Structural water
2. Hygroscopic water
3. Capillary water

# structural water :
Its forms is crystal structure of soil minerals in chemically combine state, such water cannot removed by normal drying process in oven.

Soil Compaction

# INTRODUCTION
The compact properties of soil is the compaction, if you visualized when any detachable material use to blows then comparessive force increses may result compact. In the engineering we  compact of soil for different purposes :
• To increse the shear strength.
• To increse bearing capacity.
• To decrease the permeability.

Gravel v/s sand ; silt v/s clay

Gravel v/s sand
# sand size is ( 0.075 mm to 4.75 mm)
# gravel size (4.75 mm to 80 mm)
# if we spread the soil in the flat surface and can see more than 50 % with our naked eyes then that is called course grained soil.
# if more than 50 % passing by sieve then sized <4.75 then we can say that is sand.

Classification of soil

There are many groups of soil classification but some of major group are :
• Massachusetts institute technology system (MIT)
• Textural soil classification system

Flow index, Toughness index; Relative consistency; Liquid index, sesitivity, Unconfined compressive strength;Activity of clay,void ratio

Flow index:
# Flow index is slope of semi log plot of no of blows corresponding to the water content is called flow index.
# It provides to measure the shear strength of soil.
# lower flow index better shear strength.
Flow index = (w1-w2)/log (N1/N2)
Denoted by I sufx (f).
Toughness index :

Determination of specific gravitybof soil

DEFINITION
 Specific gravity G is defined as the ratio of the weight of an equal volume of distilled water at
that temperature both weights taken in air.
 APPARATUS USED
1. Pycnometer
2. Balance to weigh the materials (accuracy 10gm).
3. Wash bottle with distilled water.
4. Alcohol and ether.
PROCEDURE

Determination of cosistency

# liquid limit :
Take 120gm of dried soil which can sieve by 425 micron and mixed it by distilled water. Then the paste of soil made that paste is kept in the cup and leveled it with spatula. Use standard grooving tool, a groove cut in the soil pat formed in the cup. The cup is blowed by the manual operation by

Soil aggregate property

#Relative density :
Relative density is one of the soil aggregate property. Which determines the relative compactness of the soil as very loose, loose, medium, dense, very dense.
Relative density is given by : 

Hydrometer analysis ( stroke's law)

The grain size less than 75 micron cannot be obtained by seive analysis. To determined the the grain size less than 75 micron, hydrometer analysis performed.