Question

The ground conditions at a site are shown in the figure below

Water table is at ground level
Water content = 20%
Specific gravity of solids = 2.7
Unit weight of water = $10kN/m^3$

The total stress, pore water pressure and effective stress $\left(kN/m^2\right)$ at the point P

• A. 75, 50 and 25
• B. 90, 50 and 40
• C. 105, 50 and 55
• D. 120, 50 and 70

Answer 1

The correct option is C 105, 50 and 55

Total stress at point

P = ${\gamma }_{sat}\times H$

= 21 $\times$ 5

$=105kN/m^2$

Pore water pressure at

P = ${\gamma }_w\times H$

= 10 $\times$ 5

$=50kN/m^2$

Effective stress at

P = Total stress - Pore water pressure

= 105 - 50

$=55kN/m^2$