Which statement about the logistics of soil compaction is true?

Which statement about the logistics of soil compaction is true?

• A. Soil compaction works best with long, gentle precipitation
• B. Compaction occurs before soil stabilization to provide a firm base
• C. Soil compaction also shapes the grade to its specified profile and crown
• D. Surface trimming shapes the compacted surface to accurate grade and crown specifications

Answer: (D)

After compaction, the finishing steps trim the surface to the exact grade and crown specifications. Compaction densifies the soil and helps it reach the intended density at the right moisture, but it doesn’t precisely set the surface geometry. Surface trimming or final grading uses graders, blades, or other equipment to remove high spots, fill low spots, and create the crown needed for proper drainage. This combination ensures the finished surface not only sits at the correct level but also sheds water along the intended path. The other ideas don’t fit because weather and moisture affect how well compaction works, but long, gentle precipitation is not a method to improve the process; moisture content should be controlled to the optimum range. The grade and crown aren’t created by compaction itself, but by the subsequent trimming/grading operation. And while stabilization can be part of subgrade treatment, the statement about compaction inherently determining grade is not accurate.

After compaction, the finishing steps trim the surface to the exact grade and crown specifications. Compaction densifies the soil and helps it reach the intended density at the right moisture, but it doesn’t precisely set the surface geometry. Surface trimming or final grading uses graders, blades, or other equipment to remove high spots, fill low spots, and create the crown needed for proper drainage. This combination ensures the finished surface not only sits at the correct level but also sheds water along the intended path.

The other ideas don’t fit because weather and moisture affect how well compaction works, but long, gentle precipitation is not a method to improve the process; moisture content should be controlled to the optimum range. The grade and crown aren’t created by compaction itself, but by the subsequent trimming/grading operation. And while stabilization can be part of subgrade treatment, the statement about compaction inherently determining grade is not accurate.