The cover zone backfill must achieve 95% of the Standard Proctor maximum density when the cover height exceeds how many inches?

Prepare for the Earthwork Level 2 Test with quizzes and detailed explanations to enhance your understanding and skills in earthwork operations. Get ready for your test with our comprehensive guide and practice material.

Multiple Choice

The cover zone backfill must achieve 95% of the Standard Proctor maximum density when the cover height exceeds how many inches?

Explanation:
When backfilling a cover zone, the risk of settlement and instability grows with thicker fills, so tighter compaction is required for taller heights. The specification calls for reaching 95% of the Standard Proctor maximum dry density when the cover height is greater than fifteen inches. The Standard Proctor test (D698) determines a maximum dry density at the optimal moisture content; expressing field compaction as a percentage of that value gives a consistent target across materials. Pushing the density to 95% in taller fills helps control long-term settlement and improve bearing capacity under load. For fills of fifteen inches or less, the requirement is typically less stringent, so the key tipping point is fifteen inches.

When backfilling a cover zone, the risk of settlement and instability grows with thicker fills, so tighter compaction is required for taller heights. The specification calls for reaching 95% of the Standard Proctor maximum dry density when the cover height is greater than fifteen inches. The Standard Proctor test (D698) determines a maximum dry density at the optimal moisture content; expressing field compaction as a percentage of that value gives a consistent target across materials. Pushing the density to 95% in taller fills helps control long-term settlement and improve bearing capacity under load. For fills of fifteen inches or less, the requirement is typically less stringent, so the key tipping point is fifteen inches.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy