Rock forecast tool: new tool for rock mass quality prediction in tunnelling

Abstract

The tool presented in this article, known as rock forecast tool (RFT), is based on the quantitative interpretation of the geological characteristics obtained from the drilling of exploratory drill holes towards the unexcavated zone of tunnels under construction. This correlates the drilling results with rock quality values that have been previously calculated on the advanced faces. The results provided by this new tool are numerical values of rock mass quality in each of the drill rods used in exploratory drilling. The results obtained by the RFT have been subjected to different statistical tests such as the Pearson's correlation coefficient, R hypothesis test, confidence intervals and covariance test. All the tests carried out show that the RFT, used as a predictor, has a high correlation with the rock mass quality values that are subsequently calculated in the excavated sections, with an R2 = 0.95.