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.
Preface
Acknowledgements
Part 1: Basic interactions between the rock mass and the TBM
1. Introduction
2. Some basic TBM designs
3. Summary of common geotechnical problems
4. The TBM excavation disturbed zone
5. Basic factors affecting penetration rate
6. Penetration rate and thrust per cutter
7. The possible influence of stress and strength ratios
8. Basic mechanism of chip formation with roller cutters
9. Tensile strength and its anisotropy
10. Penetration rate and fabric anisotropy
11. Penetration rate, joint spacing and joint character
Part 2: Q, QTBM and rock mass variability
12. TBM performance and rock mass classification
13. TBM performance and Q-system parameters
14. TBM performance and the initial requirements for 'QTBM'
15. The law of decelerating advance rates
16. Utilisation and its decay with time
17. Unexpected events and their Q-values
18. Water inflows in TBM driven tunnels
19. Consequences of limited stand-up time in TBM tunnels
20. The relationship between PR, AR and QTBM
21. Rock mass variability and its effect on predicted performance
22. Fine-tuning QTBM for anisotropy
23. Cutter wear and its effect on PR and AR
24. Effect of porosity and quartz content on gradient m and PR
25. Tunnel size effects
26. Boring in exceptionally tough, high-stress conditions
27. Revisiting cutter force effects
28. Predicting advance rates in faulted rock
Part 3: Logging, tunnel support, probing and design verification
29. TBM Q-logging and tunnel scale effects
30. Rock support methods commonly used in TBM tunnels
31. Some support design details for TBM tunnels
32. Probing and convergence measurement
33. Probing and seismic or sonic logging
34. Verifying support classes with numerical models
35. Logging rock quality and support needs
36. TBM or drill-and-blast excavations
37. Conclusions
Appendix
A1 Q-method of rock mass classification
A2 QTBM - the final version of Figure 44
A3 Input data summary for estimating PR and AR using QTBM
A4 Worked example
References
Index
Biography
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.
