A stochastic method for predicting performance of EPB TBMs working in semi-closed / open mode
A rock cutting/excavation phenomenon is in stochastic nature, which includes uncertainties in terms of decision makers. This study summarizes a new method for predicting performance (instantaneous penetration rate, daily advance rate, thrust, power, torque, and specific energy) of EPB TBMs by a stochastic method implemented into a deterministic prediction model requiring input from full-scale laboratory linear rock cutting tests. Full-scale linear rock cutting experiments using a disc cutter were performed on a block of limestone sample. Estimations were performed by using a commercially available Monte Carlo simulation program providing knowledge of probabilistic outcomes. Results of the suggested method are verified by measuring the field performance of an EPB TBM excavating a massive rock mass of limestone in semi-closed mode. Results indicate that the stochastic estimates give an opportunity to see uncertainties and variation of the experimental parameters through the use of estimated probability density function.