SOIL MECHANICS :
In our previous blog we had studied about Soil Mechanics its definition, different types of soil and our curiosity question "How soil formed" . Let's begin 


Characteristics of Soil :


Soil As a Engineering Material :

The term "Soil" means different things to different people: 

.To a geologist it represents the products of past surface processes. 
.To a pedologist it represents currently occurring physical and chemical processes. 
.To an engineer it is a material that can be:

built on: foundations to buildings, bridges. 

built in: tunnels, culverts, basements. 

built with: roads, runways, embankments, dams. 

supported: retaining walls, quays.

Soils may be described in different ways by different people for their different purposes. Engineers' descriptions give engineering terms that will convey some sense of a soil's current state and probable susceptibility to future changes (e.g. in loading, drainage, structure, surface level).


Geologist and Pedologist :

Let me clear your doubt ,Geologist is a scientist who study solid and liquid matter that constitutes the earth and Pedologist is the study of soil 




 

Size and Ranges of Grain :

The range of particle sizes in soil is very large: from boulders with dimension of over 200 mm down to clay particles less than 0.002 mm. Some clays contain particles less than 1 mm in size which behave as colloids, i.e. do not settle in water due solely to gravity.


            


Sand :

  Sand grains are generally broken rock particles that have been formed by physical weathering, or they are the resistant components of rocks broken down by chemical weathering. Sand grains generally have a rotund shape. Sand particles are visible to the naked eye. Sand and larger-sized grains are rotund. 
Rounded , Irregular, Angular, Flaky, Elongated, Flaky & Elongated are the shapes of sand particle.

Clay :

Clays include silty clays and clay-silts; there are few pure silts . Clay grains are usually the product of chemical weathering or rocks and soils. Clay particles have a flaky shape. Their thickness is very small relative to their length & breadth .