How do you determine if excavation is over-excavated or under-excavated?

• A. Measure the color of the soil to determine grade.
• B. Evaluate moisture content only.
• C. Compare excavation volume to project area.
• D. Compare actual finished elevations to design elevations; over-excavation is below design grade; under-excavation is above.

Answer: (D)

The key idea is to verify earthwork by checking elevations against the design. You determine whether excavation is over- or under-excavated by comparing the actual finished elevations to the design elevations. If the finished surface is below the design grade, it’s been dug too deep (over-excavated). If it’s above the design grade, not enough material was removed (under-excavated). This direct elevation comparison shows exactly how the work conforms to the specified grades.

Other approaches don’t directly show conformance to grade: soil color can vary for reasons unrelated to depth; moisture content doesn’t indicate whether the surface meets design elevations; and volume vs area compares quantity rather than whether the finished elevations match the design.