TBM Tunnelling in Jointed and Faulted Rock

This practical guide describes the stage-by-stage development of a method for predicting the penetration rate (PR) and the advance rate (AR) for tunnel boring machines based on an expanded version of the Q-value, QTBM. The author analyzes 145 TBM tunnels that total 1,000km in length. He then develops simple formulae to estimate PR and AR from the QTBM value and to back-calculate QTBM from performance data. The book quantitatively explains actual advance rates as high as five m/hr for one day or as low as 0.005 m/hr for several months. It also covers logging methods, empirical TBM tunnel support design, and numerical verification of support.

PrefaceAcknowledgements Part 1: Basic interactions between the rock mass and the TBM 1.Introduction2. Some basic TBM designs3. Summary of common geotechnical problems4. The TBM excavation disturbed zone5. Basic factors affecting penetration rate6. Penetration rate and thrust per cutter7. The possible influence of stress and strength ratios8. Basic mechanism of chip formation with roller cutters9. Tensile strength and its anisotropy10. Penetration rate and fabric anisotropy11. Penetration rate, joint spacing and joint character Part 2: Q, QTBM and rock mass variability 12. TBM performance and rock mass classification13. TBM performance and Q-system parameters14. TBM performance and the initial requirements for 'QTBM'15. The law of decelerating advance rates16. Utilisation and its decay with time17. Unexpected events and their Q-values18. Water inflows in TBM driven tunnels19. Consequences of limited stand-up time in TBM tunnels20. The relationship between PR, AR and QTBM21. Rock mass variability and its effect on predicted performance22. Fine-tuning QTBM for anisotropy 23. Cutter wear and its effect on PR and AR24. Effect of porosity and quartz content on gradient m and PR25. Tunnel size effects26. Boring in exceptionally tough, high-stress conditions27. Revisiting cutter force effects28. Predicting advance rates in faulted rock Part 3: Logging, tunnel support, probing and design verification 29. TBM Q-logging and tunnel scale effects30. Rock support methods commonly used in TBM tunnels31. Some support design details for TBM tunnels32. Probing and convergence measurement33. Probing and seismic or sonic logging34. Verifying support classes with numerical models35. Logging rock quality and support needs36. TBM or drill-and-blast excavations37. Conclusions AppendixA1 Q-method of rock mass classificationA2 QTBM - the final version of Figure 44A3 Input data summary for estimating PR and AR using QTBMA4 Worked example ReferencesIndex

Nick Barton has over 40 years of international experience in rock engineering, and has been involved in numerous important and iconic tunnel, cavern and rock slope projects. He has developed many tools and methods, such as the widely used Q-system, for rock classification and support selection and the Barton-Bandis constitutive laws for rock joint computer modeling. He currently teaches at the University of São Paulo and manages an international consultancy (Nick Barton & Associates, São Paulo – Oslo). Dr. Nick Barton was the 2011 recipient of the distinguished Müller Award, an award that honours the memory of Professor Leopold Müller, the founder of the ISRM (International Society of Rock Mechanics), and awarded in recognition of distinguished contributions to the profession of rock mechanics and rock engineering.