What do we mean by “Basic Properties”, “Index Properties” & “Engineering properties” in Geotechnical Engineering?
are the fundamental characteristics of the materials and provide a basis for identification and correlations. Some are used in engineering calculations.
Examples of Basic Properties include Specific gravity , Porosity , Void ratio, Moisture content , Density (Natural ,Maximum , Minimum , Relative) , Optimum moisture density , Hardness , Durability , Reactivity , Sonic-wave characteristics
Index properties define certain physical characteristics used basically for classifications, and also for correlations with engineering properties.
These include Grain-size distribution, Liquid limit, Plastic limit, Plasticity index, Shrinkage limit, Organic content, Uniaxial compression, Point-load index
Engineering properties mainly deal with material’s response to tension, compression, shear, and repeated combined actions of these three. These include Mechanical Properties as well as Hydraulic Properties.
The examples are: Permeability , Deformation moduli: static or dynamic , Consolidation , Expansion , Extension strain , Strength Unconfined / Confined/Static / Dynamic ), California bearing ratio (CBR) etc.