What is defined as the greatest angle above the horizontal plane at which materials will lie without sliding?

The concept described as the greatest angle above the horizontal plane at which materials can rest without sliding is known as the angle of repose. This term refers specifically to the maximum slope at which a material can rest stably. Factors such as the material type, size, shape, moisture content, and surface texture significantly influence the angle of repose.

Understanding the angle of repose is crucial for landscape contractors when designing slopes, retaining walls, and areas where materials such as soil or gravel are used. It helps to ensure proper drainage and stability, preventing erosion or landslides. Recognizing this concept is vital for safe and effective landscape design, making it a fundamental aspect of construction and landscaping practices.