Which statement defines swell factor?

Which statement defines swell factor?

• A. Swell factor is the ratio of loose excavated volume to in-situ solid volume
• B. Swell factor is the ratio of compacted fill volume to loose volume
• C. Swell factor is the ratio of in-situ solid volume to loose volume
• D. Swell factor is the ratio of loose volume to in-situ volume plus shrinkage

Answer: (A)

The main idea behind swell factor is how much volume increases when material is excavated and becomes loose. It is defined as the ratio of the volume of loose material left after excavation to the volume of solid material that was in place before excavation (in-situ solid volume). Because digging breaks up the material and creates voids, the loose volume is larger, so this ratio is typically greater than one. This concept is distinct from compaction, which reduces volume when you place and compress material; the other statements either describe a different concept (like compaction) or invert the ratio, or introduce terms that aren’t part of the swell factor definition.

The main idea behind swell factor is how much volume increases when material is excavated and becomes loose. It is defined as the ratio of the volume of loose material left after excavation to the volume of solid material that was in place before excavation (in-situ solid volume). Because digging breaks up the material and creates voids, the loose volume is larger, so this ratio is typically greater than one. This concept is distinct from compaction, which reduces volume when you place and compress material; the other statements either describe a different concept (like compaction) or invert the ratio, or introduce terms that aren’t part of the swell factor definition.