Difficulty: Easy
Correct Answer: Excavation (cutting) on the centre line
Explanation:
Introduction / Context:On hill roads, the contour gradient represents the alignment maintaining a specified longitudinal slope. If the chosen alignment strays upward (towards higher ground), the designed grade line lies below the ground surface, necessitating specific earthwork to bring the roadway to grade.
Given Data / Assumptions:
Concept / Approach:When the alignment shifts to higher ground, the natural surface is above the design grade. To achieve the desired grade, material must be removed along the centre line, i.e., excavation (cutting). Conversely, if the alignment deviates downhill, an embankment would be necessary to raise the formation.
Step-by-Step Solution:
Identify relative position: uphill deviation → ground level higher than design grade.Select earthwork: remove surplus material → cutting.Apply along centre line to set formation at the design gradient.Confirm that embankment would be used only for downhill deviation.Verification / Alternative check:Standard hill-road design practices illustrate that when the alignment moves into higher contours, cutting is unavoidable to maintain the target gradient.
Why Other Options Are Wrong:
Common Pitfalls:Misreading the phrase “uphill side” and prescribing fill instead of cut; always compare ground level with the designed grade line.
Final Answer:Excavation (cutting) on the centre line
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