friction angle

The friction angle is a measure of how easily a material like soil or rock resists sliding over itself or other surfaces. It indicates the internal strength of the material by representing the slope of its shear resistance. A higher friction angle means the material can hold its shape better and resist slipping under force, which is important for construction stability and slope design. Essentially, it quantifies how much "grip" or friction exists within the material, helping engineers assess its ability to support loads and prevent movement or collapse.