Rock Mass influence on Hard Rock TBM Performance Prediction
Prediction of construction time and cost is important to make a reliable choice of excavation method; to avoid schedule delays, budget overruns and to control the risk management for tunnelling projects. For hard rock Tunnel Boring Machine (TBM) projects, penetration rate is a key factor for estimating advance rates, cutter life and excavation costs. The penetration rate depends on intact rock properties, rock mass properties, and machine parameters. Rock mass fracturing factor (k) is used to include the rock mass influence on the rock boreability for performance and cost prediction for tunnel boring. The k considers the simultaneous influence of the degree of fracturing and the orientation of the plane of weakness. In the present paper, different correlations of the k have been confirmed by analyses of data from a recently finished tunnel project.