Difficulty: Medium
Correct Answer: All the above
Explanation:
Introduction / Context:
In canal design and estimation, sections may lie in embankment (banking), cutting, or a combination. Basic geometric relations for trapezoidal sections and empirical berm widths tied to full supply depth (FSD) are standard checks in preliminary design and quantity takeoff.
Given Data / Assumptions:
Concept / Approach:
For a trapezoid, area A in cutting can be written A = Bd + Sd^2 when S represents the sum of the two side-slope run factors. Embankment (bank) area follows an analogous form. Classification relative to NSL determines whether the canal is in banking, cutting, or mixed, guiding berm width prescriptions (e.g., 3d for full banking, 2d for mixed situations), as adopted in many textbooks and departmental practices.
Step-by-Step Solution:
Verification / Alternative check:
Dimensional reasonableness: each term in the area expressions has units of area; berm rules align with conventional thumb-rule practices used for preliminary sizing.
Why Other Options Are Wrong:
Common Pitfalls:
Confusing whether S denotes one side slope or combined; forgetting that berm rules are thumb-rules and may be tuned by local standards, stability checks, and right-of-way limitations.
Final Answer:
All the above
Discussion & Comments