A Rock Mass Rating system for predicting TBM utilization

摘要

Prediction of utilization based on rock mass properties is critical for any mechanized tunnelingrnproject, since the utilization have an influence on duration and costs of project. Using some case studies includingrnQueens, Milyang, Manapouri, Karaj, Varzo, Maen, Pieve mechanized tunneling project around the world, thernattempt is made to estimate utilization via Rock Mass Rating (RMR) System herein. It is concluded that thernmachine utilization has some reasonable correlations with RMR; however, this relationship is depend on not onlyrnrock mass properties but also machine specifications. In other words, the utilization may change with both rockrnmass conditions and utilized machine type. Due to that rock properties and other related downtimes should bernexamined together to obtain the reliable equations for predicting the utilization. Further, developed relationshipsrnmay be used for similar rock type to estimate utilization from RMR.