How is the "angle of repose" defined?

The angle of repose is defined as the steepest angle at which soil or rocks can remain stable without sliding down due to gravity. This concept is critical in various fields, including civil engineering, geology, and earthworks, as it determines how steeply a slope can be formed without risking landslides or erosion.

Materials with different properties have different angles of repose, influenced by factors such as the shape, texture, and moisture content of the particles. For instance, coarse, angular particles typically have a higher angle of repose compared to fine, rounded particles. In practical applications, understanding the angle of repose helps engineers and construction professionals design stable slopes and foundations, ensuring safety and integrity in construction projects.

The other options describe different aspects of civil engineering but do not accurately define the angle of repose. For instance, while drainage is important in earthworks, the angle of repose specifically relates to the stability of materials rather than the movement of water.