The piping failure in a hydraulic structure can be controlled by
- ADecreasing the base width of the hydraulic structure
- BIncreasing the seepage through the core
- CProving vertical cutoff walls below the hydraulic structureCorrect
- DProviding impervious blanket in the downstream of the structure
Solution
Concept
Control of piping
Step-by-step solution
1. Piping is controlled by increasing the seepage path and reducing the exit gradient. 2. A vertical cutoff below the structure does this.
Explanation
Cutoffs lengthen the creep path.
Why the other options are wrong
A reduces the path; B increases seepage; a downstream blanket would not reduce the exit gradient (a filter or loaded filter would).
Shortcut
Cutoff/upstream blanket reduce piping.
Correct answer: C) Proving vertical cutoff walls below the hydraulic structure