What does rock mass rating (RMR) measure?

Rock Mass Rating (RMR) is a widely used system that assesses the quality and stability of rock formations, which is crucial in mining and geotechnical engineering. It takes into consideration factors such as the rock's strength, the condition of the rock discontinuities, the spacing of these discontinuities, groundwater conditions, and any geological features that may affect stability.

By evaluating these parameters, RMR allows engineers and geologists to predict how the rock mass will behave under different conditions, such as excavation or loading, thus helping in the planning and design of safe mining operations. Understanding the quality and stability of rock formations is essential in determining the safety of underground works and the ability to implement excavation techniques properly.

Other options focus on different aspects of mining or geological assessments that are not directly related to the assessment of rock quality and stability. For example, measuring the depth of mineral deposits pertains to resource estimation rather than stability; assessing the impact on local ecosystems involves environmental studies; and determining the financial viability of operations concerns economic feasibility rather than geological integrity.