QUESTION: When we need to find the normal stress at a particular depth in the submerged soil mass, why do all the textbooks use the SATURADTED unit weight of soil, instead of the SUBMERGED unit weight?
I have been struggling with this fundamental question for a while now.
It's in all the soil mech books out there.
It relates to the calculation of normal stress vertically from the top layer, down.
The soil mass in question is submerged under a volume of water.
(Please see figure attached
)
The soil mass is very clearly submerged.
Therefore, wouldn't the stress at a depth be LESS in a submerged mass vs. a saturated mass?
Clearly yes, because the unit weight submerged is less than the saturated unit weight.
So why do we still use the saturated unit weight?
Thank you!
I have been struggling with this fundamental question for a while now.
It's in all the soil mech books out there.
It relates to the calculation of normal stress vertically from the top layer, down.
The soil mass in question is submerged under a volume of water.
(Please see figure attached
The soil mass is very clearly submerged.
Therefore, wouldn't the stress at a depth be LESS in a submerged mass vs. a saturated mass?
Clearly yes, because the unit weight submerged is less than the saturated unit weight.
So why do we still use the saturated unit weight?
Thank you!