What will be the dry density of soil if soil has bulk density of 22 kN/m³ and water content 10%:
Try it first: pick an option, then read the explanation.
Correct answer: D. 20.0 kN/m³
Detailed Explanation
Given: bulk density γb = 22 kN/m³, water content w = 10% = 0.1.
γd = γb/(1+w) = 22/1.1 = 20.0 kN/m³
This is another direct, single-step application of the bulk-to-dry density conversion already used repeatedly in this topic (Q3, Q7, Q9, Q11, Q35).
Key Concepts for Students
- γd = γb/(1+w) is worth being fully automatic by now, given how frequently it appears across this question set.
- Note that 22/1.1 conveniently gives a clean round number (20.0), which is a useful arithmetic double-check when solving under exam time pressure.
- Dry density values in the 18-20 kN/m³ range are typical for well-compacted granular fills.
- This formula is the same one used for field compaction quality control, converting measured bulk density and moisture content into a comparable dry density value.