Bayesian Updating for Rock Properties Based on a Rock Database

In drill and blasting tunneling method, a quantitative evaluation of geological conditions by drilling energy obtained from computer jumbos is being applied. In this study, a multivariate normal distribution model was developed to estimate geotechnical properties from drilling energy, and tunnel excavation analysis was conducted using the developed multivariate normal distribution model. The results confirmed that the confidence zone of the predicted values for both settlement and convergence covered the measured values. Furthermore, results of an attempt to update the multivariate normal distribution model using a data assimilation technique suggested the possibility of improving the prediction accuracy.