Estimating Practice Exam

What concept describes the increase in volume when soil or gravel is excavated?

1. Void ratio

2. Swell factor

3. Density factor

4. Volume ratio

The correct answer is: Swell factor

The swell factor is the concept that describes the increase in volume that occurs when soil or gravel is excavated from its original state. When soil is dug out, it typically undergoes a change in structure, leading to an increase in volume as the particles settle and arrange themselves differently when they are no longer compacted by the weight of the overlying material. This phenomenon is crucial in excavation and earthworks because it affects the calculations for the amount of material that needs to be moved or transported. Understanding the swell factor allows engineers and estimators to accurately predict how much material will occupy a given volume after excavation, ensuring that project costs and logistics are based on realistic expectations. The other concepts mentioned, such as void ratio, density factor, and volume ratio, are related to soil mechanics but do not specifically address the increase in volume due to excavation. The void ratio refers to the amount of void space in a material relative to its solid particles, the density factor relates to the mass per unit volume of a material, and the volume ratio is a general term that may not directly pertain to the swell phenomenon.