Correct Answer - Option 3 :
Thixotropy
Thixotropy:
The loss of strength of soil due to remoulding is partly due to the change in soil structure and partly due to disturbance caused to water molecules in the absorbing layer.
Some of these changes are reversible. If a remoulded soil is allowed to stand, without loss of water, it may regain some of its lost strength. In soil engineering, this gain in strength of the true soil with the passage of time after it has been remoulded is called thixotropy.
Sensitivity:
Sensitivity is defined as the ratio of unconfined compressive strength of the clay in the undisturbed state to the unconfined compressive strength of the clay in the remoulded state.
\({{\rm{S}}_{\rm{t}}}{\rm{ = }}\frac{{{{\left( {{\rm{UCS}}} \right)}_{{\rm{undisturbed}}\;{\rm{state}}}}}}{{{{\left( {{\rm{UCS}}} \right)}_{{\rm{remoulded}}\;{\rm{state}}}}}}\)
Relative Density:
Relative density is the measure of the compactness of cohesionless soil.
Relative density represents whether the soil is closest to its densest state or loosest state.
The relative density of soil = \(\frac{{{{\rm{e}}_{{\rm{max}}}}{\rm{ - \ }}{{\rm{e}}_{{\rm{nat}}}}}}{{{{\rm{e}}_{{\rm{max}}}}{\rm{ -\ }}{{\rm{e}}_{{\rm{min}}}}}}\)