In earthwork, what is meant by the term "lift"?

The term "lift" in earthwork refers specifically to a layer of soil that is placed upon another soil layer. This concept is fundamental in excavation and grading processes where materials are moved, compacted, or filled in layers to achieve desired densities and stability. Each lift must be properly compacted or treated before the next lift is added on top. This practice is crucial for ensuring the strength and integrity of the overall soil structure, particularly in projects like foundations, roadways, or grading for landscaping.

In contrast, the other choices do not accurately capture the definition of a "lift." A trench being excavated to a certain depth describes a specific excavation type rather than a construction layer concept. The total volume of soil moved is a broader term related to project quantification and doesn't denote a specific layering process. The depth of an excavation pertains to the vertical measurement of the soil removed but does not reflect the notion of layers being systematically constructed upon one another. Thus, recognizing a lift as a layer of soil is key to understanding effective earthwork practices.