What is the primary purpose of the described data collection method in this context?

• A. To measure soil color
• B. To assess plant growth
• C. To determine the dry density
• D. To evaluate compaction energy

Answer: (C)

The main idea here is to determine how well the soil has been compacted by measuring its dry density. In earthwork, achieving proper density is the goal because higher density means fewer voids, better support for loads, and better stability. The data collection method described is used to obtain a dry density value in the field (or lab), which you then compare to project specifications to decide if additional compaction is needed. While compaction energy influences how dense the soil becomes, the method’s purpose is to quantify the resulting density, not to measure the energy applied. Measuring soil color or plant growth doesn’t provide the needed metric of compaction quality, so they aren’t the primary purpose of this data collection.