Prólogo escrito por el Profesor Z.T. Bieniawski (Versión original en inglés)

I am pleased to be requested to preface this computer program and wish its developers and users every success in their professional endeavours.

Spanish engineers and geologists have made important contributions for better understanding and utilization of the Rock Mass Rating (RMR) classification system. Nevertheless it is appropriate to emphasize that the RMR system or other classification methods is not to be considered as substitutes for engineering design. It should be best applied in conjunction with rock mass monitoring and analytical studies to formulate an overall design rationale compatible with the design objectives and site geology.

The purpose of arriving at a RMR value for a rock mass is to quantify the rock mass quality, estimate its engineering properties, provide the reference basis for expected tunnelling conditions, and recommend suitable tunnel reinforcement measures.

In this respect, the RMR system is most effective for preliminary, planning purposes as well as for use during the actual tunnel construction. This computer program determines the RMR ratings and thus reduces the ambiguity found in descriptive, non–rating classification methods. The specific RMR values so obtained can be conveniently applied to estimate the strength and deformation parameters of a rock mass. In addition, GEOROCK 07 forces the user to consider the most important geologic parameters and combine them into an overall engineering index of rock mass quality, for use in tunnel design and construction.

 But, like with every computer program, two issues are important: 1) the reliability of the input data, and 2) clear understanding of what and how is being calculated – so that all the assumptions and procedures are properly considered.

Finally, it is always a good engineering practice to cross–check one's results; accordingly, the RMR system should not only be used on its own but also in conjunction with the Q–system as well as with the NATM or TBM tunnelling methods.

And with these words, all it remains for me is to wish all the users: Good luck!

Z.T. Bieniawski. Arizona, USA.