Empirical Design Methods

These methods are based on the use of the different geomechanical classification systems: RQD, RMR, Q. Several diagrams exist that correlate the value of RMR,RQD or Q with the different support elements needed to guarantee stability for a certain geometry. These methods have the advantage of being able to give an easy and quick answer for the support design, but as they are empirical, their result must be taken as a rough approximation valid just for preliminary studies