国际知名岩石力学专家Nick Barton博士讲座

  时间:2013年3月4日全天,3月5日全天(周一,周二)

  地点:土建与水利学院三楼学术报告厅

  授课人简介:

 

Nick Barton,博士,国际Nick Barton & Associates公司董事长。1966年于英国伦敦大学国王学院获土木工程学士学位,1971年于英国帝国理工大学获博士学位;1971-1980年在挪威国家岩土工程研究所(NGI)任高级工程师,2000年创办了Nick Barton & Associates公司,2001年起任NGI高级顾问。作为国际知名岩石力学顾问专家,Nick Barton博士被应邀到多达35个国家参与解决复杂的岩石力学问题,有着40多年的工程实践经验,其研究领域涉及公路铁路隧道、大型水电工程地下洞室群、大坝工程、核废料处理、边坡稳定性、灌浆等。

  授课内容安排:
3月4日(星期一)
上午09.00-10.30 1. INTRODUCING Q-SYSTEM OF ROCK MASS CHARACTERIZATION
Background, motivation, characteristics of Q. The six Q-parameters explained with numerous examples, including Q-roughness Jr-parameter links to the more sophisticated JRC. Q-histogram logging. Q-Tables and general logging advice. Also Q-RMR comparison.

TEA BREAK / QUESTIONS
上午11.00-12.00      2.  LINKING Q TO USEFUL PARAMETERS FOR DESIGN
Core logging examples, including faulted and weathered rock. Rock mass strength estimation from Q (CC and FC). P-wave velocity, and effects of weathering and depth on velocity, and the links to Q. Deformation modulus estimation at depth, from seismic velocity or from Q, for dam-site characterization. Hydropower tunnel and cavern convergence estimation, from empirical Q formulae.

LUNCH BREAK

下午13.30-14.30  3. TUNNEL SUPPORT SELECTION FROM Q CLASSIFICATION, AND SUPPORT ELEMENT PROPERTIES
Historical development of Q for B+S(mr) mesh-based support. NMT tunnel support philosophy, as applies in diversion tunnels and access tunnels. Tunnel support design with B+S(fr) fibre-reinforced shotcrete support. Temporary or permanent support. Physical performance of S(fr) and bolting. Reinforced RRS arches for bad ground. Cost versus Q and tunnel size.

下午14.30-15.30    4. PRE-GROUTING AND WATER CONTROL

Water control methods in tunnels. Simplified interpretation of Lugeon tests for pre-injection grout design. Comparing joint aperture estimates with available grout-particle sizes. High-pressure injection concepts and pressure decline. Some performance and volumetric data from pre-injected tunnels. Rock quality improvement from Q-parameter improvement, by high-pressure pre-injection.

TEA BREAK / QUESTIONS

16.00-17.00   5. TBM PERFORMANCE AND PROGNOSES

Fundamentals of cutter action, rock breakage and cutter wear. Penetration rate, advance rate and aspects of time and utilization. Case record analysis and geological reasons for deceleration. Performance with open, single shield and double-shield machines. The Qtbm model of performance prognosis. Examples of Qtbm application from Chile, Brazil, Spain, Norway.

DISCUSSION AND QUESTIONS 17.00-17.30

3月5日(星期二)
09.00-10.00  6. RISK TO TBM TUNNELLING FROM FAULTS AND HIGH STRESS          

Long tunnels and TBM. Interpretation of TBM difficulties in terms of Qtbm model. The concept of ‘multiple unexpected events’. TBM tunnelling difficulties, with examples from Italy, Kashmir, Taiwan, Chile. Stress-strength and rock failure problems. Use of probe drilling and  pre-grouting in Hong Kong SSDS Tunnel F.

TEA BREAK / QUESTIONS

10.30-12.00  7.SLOPE STABILITY PRINCIPLES AND QSLOPE METHOD OF CHARACTERISING ROCK SLOPES FOR DECIDING ON SAFE SLOPE ANGLES

A slight modification of the Q-system for collecting information on slope-related Q-parameters, including ‘wedges’ made of two different joint sets, and extreme rainfall. Safe slope angles for road cuttings or benches, using core characterization, and/or seismic refraction, and/or pilot-slope logging. Rock reinforcement based on shear strength for slopes that have to be over-steepened, as at dam and spillway sites. Rockfill and large-scale rockfill characterization.

DISCUSSION / QUESTIONS

LUNCH BREAK (舜园二层午餐)

13.30-14.30  7. LESSONS FROM A SHALLOW METRO CAVERN COLLAPSE

A metro-station cavern collapsed suddenly during construction, causing the death of seven people. Numerous boreholes had indicated 3 to 4 m of rock cover beneath 16-18 m of sand, soil and saprolite. Heavy structural support was therefore used as temporary support, instead of rock bolts and shotcrete. The combination of ‘unexpected events’ combined to cause an unprecedented accident, which was ‘unpredictable in the circumstances’. The risks involved with (too) shallow metro-line and metro-station design are emphasised.

TEA BREAK / QUESTIONS

15.00-16.00  8. INVESTIGATIONS AND DESIGN OF THE LARGEST CAVERN EVER BUILT, WITH CONTRAST TO A HYDROPOWER CAVERN IN SEVERELY FAULTED ROCK

The largest cavern ever built for use by the public, effectively doubling the previous largest span, was built in jointed gneiss in Norway, for initial use in the 1994 Winter Olympic Games. Q-logging site investigation, cross-hole tomography, stress measurement and numerical UDEC-BB modelling and NMT-style permanent support design for this 62 m span cavern are described, including follow-up mapping and monitoring. The ‘Class A’ predictions of performance proved to be very accurate. A hydropower cavern in faulted rock in Taiwan with special support measures emphasises the range of problems.

16.30-17.30      DISCUSSION AND QUESTIONS