Civil Engineering (CE) Exam > Civil Engineering (CE) Questions > An irrigation canal proposed to be excavated ...
Start Learning for Free
An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:
- a)1 in 6000
- b)1 in 2000
- c)1 in 5200
- d)1 in 1265
Correct answer is option 'C'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
An irrigation canal proposed to be excavated in an incoherent alluvial...
Most Upvoted Answer
An irrigation canal proposed to be excavated in an incoherent alluvial...
Given parameters:
- Discharge (Q) = 40 cumecs
- Soil size (D) = 0.4 mm (minimum size)
- Soil type = Incoherent alluvial soil
To determine: Bed slope (S)
Formula used: Manning's formula
Manning's formula relates the flow velocity (V) in a channel to the flow rate (Q), cross-sectional area (A), wetted perimeter (P), Manning's roughness coefficient (n), and bed slope (S).
Q = AV
A/P = B/T
V = (1/n) * (R^(2/3)) * (S^(1/2))
where:
- Q = Discharge
- A = Cross-sectional area of the channel
- P = Wetted perimeter of the channel
- B = Bottom width of the channel
- T = Top width of the channel
- V = Flow velocity
- n = Manning's roughness coefficient
- R = Hydraulic radius of the channel (A/P)
- S = Bed slope
Solution:
The soil is incoherent alluvial, which means it is not very cohesive and has poor bearing capacity. Therefore, a steeper bed slope is required to prevent sedimentation and maintain the flow velocity.
Assuming a trapezoidal channel with a side slope of 1 vertical to 2 horizontal, we can calculate the dimensions of the channel as follows:
- Discharge (Q) = 40 cumecs
- Velocity (V) = 1.5 m/s (assumed)
- Cross-sectional area (A) = Q/V = 26.67 sq.m
- Wetted perimeter (P) = (B + T) / 2 * (1 + (2^2)^(1/2)) = 34.64 m (approx.)
- Hydraulic radius (R) = A/P = 0.77 m (approx.)
The roughness coefficient (n) depends on the type and condition of the channel lining, but for an unlined earthen canal, it is typically in the range of 0.025 to 0.035.
Assuming a value of 0.03 for Manning's roughness coefficient, we can solve for the bed slope (S) as follows:
V = (1/n) * (R^(2/3)) * (S^(1/2))
1.5 = (1/0.03) * (0.77^(2/3)) * (S^(1/2))
S^(1/2) = 1.5 * 0.03 / 0.77^(2/3)
S = (1.5 * 0.03 / 0.77^(2/3))^2
S = 1/5198.8
Therefore, the required bed slope for the irrigation canal is 1 in 5200 (option C).
- Discharge (Q) = 40 cumecs
- Soil size (D) = 0.4 mm (minimum size)
- Soil type = Incoherent alluvial soil
To determine: Bed slope (S)
Formula used: Manning's formula
Manning's formula relates the flow velocity (V) in a channel to the flow rate (Q), cross-sectional area (A), wetted perimeter (P), Manning's roughness coefficient (n), and bed slope (S).
Q = AV
A/P = B/T
V = (1/n) * (R^(2/3)) * (S^(1/2))
where:
- Q = Discharge
- A = Cross-sectional area of the channel
- P = Wetted perimeter of the channel
- B = Bottom width of the channel
- T = Top width of the channel
- V = Flow velocity
- n = Manning's roughness coefficient
- R = Hydraulic radius of the channel (A/P)
- S = Bed slope
Solution:
The soil is incoherent alluvial, which means it is not very cohesive and has poor bearing capacity. Therefore, a steeper bed slope is required to prevent sedimentation and maintain the flow velocity.
Assuming a trapezoidal channel with a side slope of 1 vertical to 2 horizontal, we can calculate the dimensions of the channel as follows:
- Discharge (Q) = 40 cumecs
- Velocity (V) = 1.5 m/s (assumed)
- Cross-sectional area (A) = Q/V = 26.67 sq.m
- Wetted perimeter (P) = (B + T) / 2 * (1 + (2^2)^(1/2)) = 34.64 m (approx.)
- Hydraulic radius (R) = A/P = 0.77 m (approx.)
The roughness coefficient (n) depends on the type and condition of the channel lining, but for an unlined earthen canal, it is typically in the range of 0.025 to 0.035.
Assuming a value of 0.03 for Manning's roughness coefficient, we can solve for the bed slope (S) as follows:
V = (1/n) * (R^(2/3)) * (S^(1/2))
1.5 = (1/0.03) * (0.77^(2/3)) * (S^(1/2))
S^(1/2) = 1.5 * 0.03 / 0.77^(2/3)
S = (1.5 * 0.03 / 0.77^(2/3))^2
S = 1/5198.8
Therefore, the required bed slope for the irrigation canal is 1 in 5200 (option C).
Attention Civil Engineering (CE) Students!
To make sure you are not studying endlessly, EduRev has designed Civil Engineering (CE) study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Civil Engineering (CE).
|
Explore Courses for Civil Engineering (CE) exam
|
|
Similar Civil Engineering (CE) Doubts
Top Courses for Civil Engineering (CE)View all
An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer?
Question Description
An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer? for Civil Engineering (CE) 2024 is part of Civil Engineering (CE) preparation. The Question and answers have been prepared according to the Civil Engineering (CE) exam syllabus. Information about An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for Civil Engineering (CE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer?.
An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer? for Civil Engineering (CE) 2024 is part of Civil Engineering (CE) preparation. The Question and answers have been prepared according to the Civil Engineering (CE) exam syllabus. Information about An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for Civil Engineering (CE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer?.
Solutions for An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for Civil Engineering (CE).
Download more important topics, notes, lectures and mock test series for Civil Engineering (CE) Exam by signing up for free.
Here you can find the meaning of An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer?, a detailed solution for An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer? has been provided alongside types of An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice An irrigation canal proposed to be excavated in an incoherent alluvial soil of minimum size 0.4mm, for carrying a discharge of 40 cumecs, should have a bed slope of:a)1 in 6000b)1 in 2000c)1 in 5200d)1 in 1265Correct answer is option 'C'. Can you explain this answer? tests, examples and also practice Civil Engineering (CE) tests.
|
|
Explore Courses for Civil Engineering (CE) exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup