Which characteristic defines stable rock in excavation?

The defining characteristic of stable rock in excavation is that it is solid mineral material capable of being excavated with vertical sides. This means that stable rock has the necessary strength and cohesion to maintain its structure when excavated. Unlike other materials, stable rock does not require excessive support or shoring when excavating, allowing operators to cut vertical faces safely.

In the context of excavation, stable rock provides a reliable foundation and is essential for various construction projects, ensuring the integrity and safety of structures built above them. Additionally, the ability to excavate with vertical sides simplifies the excavation process and reduces the risk of collapse, making it crucial for operators to identify and understand the properties of stable rock in their work.