When density is referred to in earthworks, it is defined by which of the following?

When density is referred to in earthworks, it pertains to the relationship of mass to volume, particularly in regard to the weight of soil and water. This concept is critical because the density of soil, which combines the weight of solids, water, and air, directly impacts various factors such as stability, compaction, and drainage.

In earthwork projects, understanding the weight of soil and water helps engineers determine how much material is needed for compaction and how the soil will behave under load. For example, a higher moisture content can increase the weight of the soil, consequently affecting its density.

The other options, while related to the characteristics of earth materials, do not accurately define the concept of density. The volume of air does not contribute to the overall density as it is the mass of solids and liquids that primarily determine soil density. The proportion of soil types can impact the density but is not a defining feature in the measurement itself. Temperature can affect the properties of soil and moisture content but is not directly linked to the definition of density in this context.