The Rock Mass Rating (RMR) System is a classification system for rocks. RMR combines geologic parameters of influence and represents them with an overall index of rock mass quality, ranging from 0 to 100. The higher the RMR value is, the more stable the rock is. These values aid in the design and construction of excavations in rock, such as tunnels, mines, slopes and foundations. RMR is calculated using the following formula:
RMR=Intact Rock Strength + RQD + Discontinuity Spacing+ Discontinuity Orientation+ Groundwater Conditions
There are many similarities between Q, and RMR and both can be used to classify rock stability. The use of both classification systems in stability analysis gives a check of the estimates made.