Question

At a certain point in the floor of weir, the uplift pressure head due to seepage is 4.5m. If the relative density of concrete is 2.5, the minimum thickness of floor required at this point to counteract the uplift pressure is

• A. 1 m
• B. 2 m
• C. 3 m
• D. 4 m

Answer 1

The correct option is C 3 m

To counter the uplift pressure at the point,
Buoyant weight of concrete = seepage force on area

$(2.5-1)\times t\times 1=4.5\times 1$
t = 3 m