In case of long tunnels, the drainage system consists of sump wells which are located at a regular interval of about
- A50 m to 100 m
- B100 m to 200 m
- C200 m to 300 m
- D300 m to 500 mCorrect
Solution
Concept
Sump well spacing in tunnel drainage
Formula
NONE
Step-by-step solution
1. In long tunnel construction, effective drainage management is required to handle seepage water. 2. Drainage systems collect water into sump wells distributed along the tunnel length. 3. These sump wells are typically located at regular intervals of 300 m to 500 m to pump out accumulated water. Answer: D
Explanation
In long tunnels, drainage water is collected and pumped out using sump wells spaced at regular intervals along the length. These sumps are typically positioned every 300 m to 500 m to ensure efficient collection and prevent excessive water accumulation. This spacing balances pumping efficiency with installation costs along the tunnel alignment.
Why the other options are wrong
A) This interval is too short and economically inefficient for locating sump wells in long tunnels. B) This range represents a shorter distance than the required standard spacing of 300 m to 500 m. C) Sump wells are placed at larger intervals than 200 m to 300 m in long tunnel drainage systems.
Shortcut
Sump wells in long tunnels are spaced at 300 m to 500 m.
Common mistake
Confusing the spacing of sump wells in long tunnels with smaller drain intervals like 100 m to 200 m.
Correct answer: D) 300 m to 500 m