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
Casagrande’s apparatus is used to determine _______.
In oven drying method, the soil sample is kept in the oven for about ________ hours.
In consistency of soil, the limits are expressed in terms of ______.
An empty container weights W1 container with soil sample weights W2, container and oven dried sand weights W3. The Moisture Content of soil is ___________.
- Known the soil properties: e - void ratio, n - porosity, w - water content, G - specific gravity, S - degree of saturation, γ sat - Saturated unit weight of soil; and γ w - unit weight of water. From among the following relations, identify the relation that is INCORRECT.
