Question

SITUATION 2: EFFECTIVE STRESS

An engineer investigates a granular soil deposit, 4 meters thick, overlaying a 5 meter thick clay. The
water table is present between the interface of the granular soil and the clay. The moist unit weight
of the sand is 15.6 kN/m3

, while the clay has a saturated unit weight of 17.8 kN/m3

a.) What is the vertical effective stress at the bottom of the clay?

b.) If the water table rises to the level of the soil surface, what is the effective stress at the bottom
of the clay layer.

c.) If the same soil structure is below a river that is known to be 3 meters deep, what is the
effective at the bottom of the clay layer?

Answer 1