Which of the following methods is/are used for controlling groundwater during excavation? i. Sump pumping ii. Deep well system iii. Well point systems
- AOnly (i)
- BOnly (i) and (ii)
- COnly (ii) and (iii)
- D(i), (ii) and (iii)Correct
Solution
Concept
Groundwater control methods during excavation
Formula
NONE
Step-by-step solution
1. Dewatering and controlling groundwater during excavation can be achieved using sump pumping, well point systems, or deep well systems depending on site conditions. 2. All three listed techniques (i, ii, and iii) are standard methods employed in civil engineering practice. 3. Therefore, options (i), (ii), and (iii) are all correct. Answer: D
Explanation
Controlling groundwater during excavation can be achieved through various dewatering methods depending on soil conditions and water table depth. Sump pumping, deep well systems, and well point systems are all standard engineering techniques used to lower groundwater. Therefore, option D is correct as all three methods are used.
Why the other options are wrong
A) Sump pumping is not the only groundwater control method used in excavation. B) Well point systems are also effective groundwater control methods alongside sump pumping and deep wells. C) Sump pumping is also a valid method for controlling groundwater during excavation.
Shortcut
Remember S-D-W: Sump, Deep well, and Well point systems are ALL valid groundwater control methods.
Common mistake
Selecting option A or B by assuming sump pumping is the only method used for controlling groundwater.
Correct answer: D) (i), (ii) and (iii)