ETC Surveying & Site Measurement Flashcards

What is the formula for calculating the area of a triangular parcel using base and height?

Answer: Area = (base x height) / 2

The area of a triangle equals one-half of the product of its base and perpendicular height.

In construction staking, what is the purpose of an offset stake?

Answer: To mark a reference point offset from the actual feature so it survives excavation

Offset stakes are placed a set distance away from the actual construction feature so they are not destroyed when digging or grading begins.

What does a contour interval of 2 feet on a topographic map indicate?

Answer: Each contour line represents a 2-foot change in elevation

The contour interval is the consistent vertical elevation difference between adjacent contour lines on a topographic map.

What does an as-built survey document?

Answer: The actual constructed positions and elevations of completed improvements

An as-built survey records the true final locations, dimensions, and elevations of constructed features, which may differ from design drawings.

What is the significance of a 1:1 slope in cut-slope design?

Answer: For every 1 foot of vertical drop, the slope extends 1 foot horizontally

A 1:1 slope means the horizontal run equals the vertical rise, resulting in a 45-degree angle typical for stable cohesive soils.

Which method is used to transfer an elevation from a benchmark to a distant point using a series of intermediate setups?

Answer: Differential leveling (fly leveling)

Differential leveling uses a series of backsight and foresight readings through multiple instrument setups to carry an elevation over long distances.