Question

How does a shift in the ground surface affect the effective stress? Justify your answer mathematically.

Answer 1

● The shift in the ground surface cause changes in the effective stress.

The change in the effective stress due to shift in ground surface is because of change in overburden pressure above the soil surface.

The shift in ground surface is acts like change in overburden pressure when shift is positive the change is also positive and the effective stress is increases and when shift is negative the effective stress decreases.

The decrease or increase in the effective stress is equivalent to the overburden stress for amount of shift.

◆ Mathematically we can say that:-

Changed effective stress = previous effective stress + (or) - overburden stress due shift.

changed eff. stress = prev. eff. stress + (or) - yD

where

y= bulk density of shifted soil

D= depth of shift

◆ +(or )- depends on the shift is positive or negative.

Thank you.