Index Properties of soil

Soil varies from place to place and hence its properties also. It is really impossible to test all type of soil for evaluation of engineering properties of soil as it is practically very time taking and uneconomical process. To address this issue we can group the soil and the soil in the same groups shows almost same engineering properties. To categories the soil in groups we have to use some parameters, these parameters are Index Properties of soil. One can perform different tests known as classification to measure the index properties of soil. We can group all properties into two major groups.

1. Soil grain properties : As name suggests these properties are influenced by the individual grains. Hence in under this category we keep mineralogical composition, specific gravity of solids, size and shape of grains.

2. Soil Aggregate properties : These properties are important from the soil aggregate behaviour. As you can imagine this group is more dominant for engineering behaviour of the soil. This group consists of consistency of soil, soil stress history, mode of soil formation.

List of the different properties of the soil under each category is given here, and for the explanation of the each properties I will give one separate long post.

1. Soil grain properties

   • Grain shape

   • Grain size distribution

     • Dry sieve analysis

       • Coarse grain analysis

       • Fine grain analysis

     • Wet sieve analysis

       • Hydrometer Analysis

       • Pipete method

2. Soil aggregate properties

   • Consistency of clays (Atterberg limits)

     • Liquid limit

     • Plastic limit

     • Shrinkage limit

   • Permeability

   • Unconfined compressive strength

   • Sensitivity and Thixotropy

   • Void ratio, Porosity and Unit weight

   • Relative density and density index

   • Activity

As engineering properties are the important take home from the geotechnical engineering. In this post a big picture of soil index properties is given. Interested learner can see the other post for the detail of each properties.