During a rapid field test for identifying fine-grained soil, a wetted sample is shaken vigorously in the palm of the hand. If the surface quickly becomes glossy or wet (exhibits 'quicker' behavior), and the gloss disappears immediately upon squeezing the sample, which soil type is the sample most likely to be?
Inorganic silt (ML)
The dilatancy (shake) test is a field identification test for fine-grained soils:
- Wet soil sample is shaken vigorously in the palm
- A quick reaction (surface becomes wet/glossy rapidly, gloss disappears immediately on squeezing) indicates non-plastic, silty soil (ML — inorganic silt of low plasticity) — this is due to high dilatancy (water moves freely in non-plastic soils)
- Slow reaction: Silty clay (CL, ML)
- No reaction: High-plasticity clay (CH) — clay holds water tightly due to high plasticity
The 'quicker' behavior described is the hallmark of inorganic silt (ML).
Important Questions from Index Properties
______ is the ratio of the volume of voids to the total volume of the given soil.
The liquid limit is determined from the Casagrande apparatus. The apparatus consists of a semi-spherical brass cup that is repeatedly dropped onto a hard rubber base from a height of:
A pycnometer is used to determine
Who proposed this formula, k = 200D2ee2 where, k = coefficient of permeability, De = Effective Grain size?
The ratio of a given volume change in a soil, expressed as percentage of the dry volume, to the corresponding change in water content is called
