What is the primary cause of volume change in saturated soils when subjected to vertical stress?

Movement of water out of the voids.

Fill in the blank: The three components of total settlement are elastic settlement, primary consolidation, and ______.

Secondary compression.

True or False: In coarse soils, volume change occurs immediately due to low permeability.

False. In coarse soils, volume change occurs immediately due to high permeability.

What is the term for the maximum effective stress experienced by soil compared to its current effective stress?

Preconsolidation stress (σ'pc).

Riddle: I describe how water flows through soil but can be defined as the ease with which it flows. What am I?

Permeability.

Which parameter represents the compression of soil per unit original thickness due to a unit increase of pressure?

Coefficient of volume compressibility (mv).

Fill in the blank: The relation of void ratio to effective stress can be depicted as an arithmetic plot or a ______ plot.

Semi-log.

True or False: For normally consolidated clays, the overconsolidation ratio (OCR) is always less than 1.

False. For normally consolidated clays, OCR = 1.

What does the coefficient of compressibility (av) indicate about soil under one-dimensional compression?

It indicates how compressibility decreases as effective stress increases.

Riddle: I am a ratio of the maximum effective stress to the current effective stress, known to influence soil behavior. What am I?

Overconsolidation ratio (OCR).

Which empirical procedure is commonly used to estimate preconsolidation stress in soils?

Casagrande's construction.

Fill in the blank: The flow equation in one-dimensional consolidation can be expressed as the hydrodynamic equation of ______.

One-dimensional consolidation.

True or False: The time factor (T) in consolidation relates the degree of consolidation to the time elapsed since loading.

True.

What is the equation used to calculate the coefficient of consolidation (Cv) at 90% consolidation?

Cv = (T90 × d²) / t90.

Riddle: I change the pore pressure in soil when vertical load is applied and then dissipated over time. What am I?

Excess pore water pressure (u).