Types of Soils

  1. Types of Soil 

The soils are classified into 2 types according to formation.

  1. Based on Location

    1. Residual soils: When the soil is available at its formation just about the parent of it is known as residual soil. These soils are available at shallow depths and engineering properties vary from the top layer to the bottom layer. The bottom layer of soil resembles that of parent rock in many aspects.

    2. Transported soils: When the soil is available at a place away from the plays of its villages, it is called transported soil. These soils are available at considerable depths. The different ways of transporting entry, depositing solids, air, water, wind, ice and gravity.   

      1. Water transported soils: The soils which are transported by the flow of water are called water transported soils. When the velocity of the water reduces, the coarse particles get deposited.

      2. Wind transported soils: The soils, which are transported by wind are called wind transported soil. A dust storm gives evidence of the soil particles carried by this method.

      3. Glacier deposited soils: The glaciers move the soils from the formation place and carry soils of varying sizes from fine grains to huge boulders.

      4.  Gravity deposited soils: Soil transported by gravity force is called talus and it consists of irregular coarse particles.

  2. Based on Cohesion
    Soils get classified as cohesive or cohesionless. 

    1. Cohesive Soil: Soil has an attraction between particles of the same type, origin and nature i.e., Cohesive soils are a type of soil that stick together. Cohesive soils are fine-grained soils such as silts and clays.  

    2. Cohesionless Soil: Cohesionless soils are the type of soils that do not adhere to each other and rely on friction to stick together. Cohesionless soils are coarse-grained soils such as sands and gravels. This type of soil is particularly relevant when it comes to erosion and stormwater runoff. As cohesive soils are less likely to or harder to erode. Therefore, it is important to know what kind of soil you have on your site to better understand how the soil will react during the events of heavy and continuous rains.​​​​​​​

Note: Classification of soils will be dealt with, in detail in the chapters ahead