Ch 9 - In situ stresses

Total stress (sigma) =(Equation)

Portion of it will be carried by water is called

The vertical component of forces at the
point of contact of the solid particles per
unit cross‐sectional area of the soil mass
is called

Cross‐sectional area =

For most soils, the value of i_cr varies from

A soil under critical hydraulic gradient is unstable and is said to be

By definition for any granular soil quick condition is possible. But soil with high
permeability (e.g. gravel or coarse sands) requires large quantity of water to maintain
critical hydraulic gradient. Therefore, the quick conditions are usually confined

Quicksand is a very real danger in dewatering excavations and other construction
facilities, where

Total stress (sigma) is the stress

Capillary action results in

Downward seepage -------- the resultant effective stress

upward
seepage ------ the resultant effective stress.