Soil mechanics,water content, void ratio, degree of saturation,porosity.density , importance of soil mechanics,soil mechanics formula,soil mechanics problem and solution. .

 Soil mechanics

In engineering soil is the unaggregated or uncemented deposits of mineral and organic particles or fragments covering large portion of the earth's crust. Soil is considered by the engineer as a complex material produced by weathering of the solid rock. The formation of soil is as a result of geological cycle continually taking place on the face of the Earth.

In short soil is the mixture of fine rock particles and voids ...voids may be filled by water or partially water and air .

Phase system 

A soil mass is,in general a three phase system composed of solid, liquid and gaseous matter.

For better understanding of the soil behaviour.it is helpful to think of these constituents as occupying separate spaces, as shown in fig.

Water content 

It is called moisture content, denoted by w .It is defined as the ratio of the weight of water to the weight of solids in a given mass soil.

w= [Ww/Ws]x100 

Note- w=>0 and no upper limit to water content.

Void ratio 

 It is defined as the ratio of the volume of voids to the volut of solids. 

e= Vv/Vs 

Note -e>0 since a soil has contain some voids but there cannot be an upper limit to the void volume. 

Porosity 

It is defined as the ratio of the volume of voids in the sample to the total volume of the soil.

n= [Vv/V]x100 

Note -  0<n<100 

Degree of saturation 

It is defined as the ratio of the volume of water to the volume of voids.

S= [Vw/Vv]x100 

Air content 

It is defined as the ratio of the volume of air voids to the volume of voids.

ac = Va/Vv 

Unit weight 

It is defined as the ratio of weight to the total volume.

Y= W/V.

Specific Gravity 

It defined as the ratio of the unit weight of solids to that of water.

Gs=Ys/Yw

Also see...... 

Self compacting concerete....