Factors Influencing the Performance of Full Face Hard Rock Tunnel Boring Machines

摘要

This report considers the major factors influencing full face hard rock tunnel boring machine (TBM) performance, both in terms of machine boreability (rock-tool interaction) and machine utilization. It is not intended to encompass all aspects of machine performance, but to concentrate on the principle elements affecting penetration rate and tool wear, and their methods of prediction, as well as the geologic factors influencing utilization. The importance of machine design and the interrelation with the tunnel environment is emphasized. Ability to place support and/or reinforcement close to the tunnel face, maintain machine stability, and cope with excessive ground water has a major effect on overall progress. Aside from information from field investigations, basic points are illustrated with case histories (European) from the literature. Rock-tool interaction is reviewed to assess the major factors influencing TBM boreability from three separate, although related methods. First, numerical models are considered with a view to their predictive potential and the foundation for a theoretical understanding of tool interaction. Second, physical models simulating the excavation process and prototype machine behaviour are discussed. These laboratory and field studies represent the major source of information from which a fundamental and practical understanding of rock-tool-machine interaction has evolved. Finally, the indices and index tests widely employed for TBM boreability predictions are evaluated. This report provides conclusions and recommendations regarding TBM operations as well as a list of references.