Question

When the reservoir is empty, the maximum vertical stress equal to ________________

(a) At heel = 2W/B and at toe = 0

(b) At heel = 0 and at toe = 2W/B

(c) At heel = toe = zero

(d) At heel = toe = 2W/B

I have been asked this question in examination.

The origin of the question is Gravity Method topic in portion Gravity Dam Design and Construction of Irrigation Engineering

Answer 1

The correct option is (a) At heel = 2W/B and at toe = 0

The explanation: The vertical stress distribution at the base when the reservoir is empty is given as –

Pmax/min = V/B [1 + 6e/B] and V/B [1 – 6e/B] where e = B/6 and V = total vertical force = weight W

Pmax = 2W/B and Pmin = 0.

The maximum vertical stress at the heel is equal to 2W/B and at the toe is zero.