Question

Uplift pressures at points E and D (Fig. A) of a straight horizontal floor of negligible thickness with a sheet pile at the downstream end are 28% and 20% respectively. If the sheet pile is at the upstream end of the floor (Fig B), the uplift pressures at points $D_{1}and{C}_1$ are

• A. 35% and 60% respectively
• B. 80% and 72% respectively
• C. 88% and 70% respectively
• D. 100% and zero respectively

Answer 1

The correct option is B 80% and 72% respectively

Uplift pressure when sheet pile is at upstream = 100 - uplift pressure when sheet pile is at downstream

Uplift pressure at
$D_1$ = 100 - Uplift pressure at D
= 100% - 20% = 80%

Uplift pressure at
$C_1$ = 100 - Uplift pressure at E
= 100% - 28% = 72%