RMR system of Bieniawski is the most widely known classification. The classificationin clude information on the strength of the intact rock material, the spacing, number and surface properties of the structural discontinuities as well as allowances for the influence of subsurface ground water and the orientation and inclination of dominant discontinuities. That classification is developed primarily for theest imation of the support require mentsin tunnels but its use has been expanded to cover many other fields.
Rock mass rating system (RMR) has been appliedin more than 268 case histories such as
tunnels, chambers, mines, slopes, foundation sand rock caverns. There asons for using RMR are,
according to Bieniawski (1989), theease of use and thever satility inengineering practice. When
apply in this classification system, one divides the rock mass into a number of structural regions
and classifie seach region separately. The RMR system uses the following six parameters, whose
ratings are added to obtain a total RMR-value
-Uniaxial compressive strength of intact rock material;
-Rock quality designation (RQD);
-Joint or discontinuity spacing;
-Ground water condition; and
The first five parameters (1-5) represent the basic parameters (RMR basic) in the
classification system. Each of these parametersis given a value. All the values are algebraically
summed for the five first given parameter sand then adjusted by the sixth parameter depending on
the joint orientation.