Rock Mass Rating system

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The Rock Mass Rating (RMR) system is a geomechanical classification system for rocks, developed by T.Z. Bieniawski between 1972 and 1973.

1 Definition
2 Classification table
3 Applications
4 Literature
5 References

[edit] Definition

The following six parameters are used to classify a rock mass using the RMR system

Uniaxial compressive strength of rock material
Rock quality designation (RQD)
Spacing of discontinuities
Condition of discontinuities
Groundwater conditions
Orientation of discontinuities

Each of the six parameters is assigned a value corresponding to the characteristics of the mountain. These values are derived from field surveys. The sum of the six parameters is the "RMR value", which lies between 0 and 100.

[edit] Classification table

Below is the classification table for the RMR system.^[1]

RMR	Rock quality
0 - 20	Very poor
21 - 40	Poor
41 - 60	Fair
61 - 80	Good
81 - 100	Very good

[edit] Applications

Rock Mass Rating has found wide application in various types of engineering projects such as tunnels, slopes, foundations, and mines. It is also adaptable for knowledge-based expert systems.

[edit] Literature

Bieniawski, Z.T. "Engineering Rock Mass Classifications", John Wiley and Sons, New York, 1989
— "The Rock Mass Rating (RMR) System (Geomechanics Classification) in Engineering Practices." Rock Classification Systems for Engineering Purposes, 17-34. Philadelphia, Pennsylvania: American Society for Testing and Materials, 1988