MATHEMATICAL AND FUZZY LOGIC MODELS IN PREDICTION OF GEOLOGICAL AND GEOMECHANICAL PROPERTIES OF ROCK MASS BY EXCAVATION DATA ON UNDERGROUND WORKS

In underground works, the continual consciousness of geological and geomechanical properties of rock mass during drilling, is of major importance to optimize the works and the equipment used. In this paper, the mathematical relationship obtained from tunnel excavations, considering percussion drilling for blasting by a drilling machine and by a tunnel boring machine (TBM) are exposed. These mathematical relationships are useful in the percussion drilling case, to adjust the drilling parameter recorder (DPR) tools, and in the case of TBM to predict the rock mass geomechanical index (RMR). Taking into account the complexity of these mathematical models obtained, as a consequence of the affected variables and their relations, a fuzzy logic model based on parameters accessible to the drilling machine has been used in tricone bit drilling.