In open-pit mines, the steepness of the walls is a delicate balance. If too steep, they collapse; if too shallow, the mine becomes unprofitable.
For massive structures like dams or bridges, rock mechanics ensures the underlying bedrock can support the load without shifting. Mining Engineering: Fundamentals and Applications of Rock Mechanics
Unlike manufactured materials like steel, rock is "natural," meaning it is rarely uniform. The fundamentals focus on characterizing these complexities: In open-pit mines, the steepness of the walls