Instructor: Peter K. Kaiser - MIRARCO

Speakers:Ming Cai - MIRARCO

Rocky Wu - Mansour Mining and Brad Simser - Noranda Technology Centre

Dany Gaudreault and Dan Lemieux - Sandvic Tamrock Canada

Fidelis Suorineni - MIRARCO

Mark Diederichs - Queen's University and John Henning - MIRARCO

Paul Germain - Atlas Copco

Location: Willet Green Miller Centre, Laurentian University, 933 Ramsey Lake Road

Day 1 - November 13, 2002

8:00 to 8:30 Registration - Coffee

8:30 - 10:00 Welcome - Introduction

-        Tunnelling sees a great emergence worldwide and engineering boundaries are being tested by tunnelling with new technologies and at much greater depth. While difficult tunnelling conditions have long been encountered and managed with appropriate tunnel construction methods, tunnelling at great depth and in hard, brittle ground poses new challenges that form the focus of this course.

Sessions 1 - Overview, Goals and Fundamentals - common ground

-         When tunnelling at depth, putting numbers to geology is essential to prevent unexpected difficulties and cost overruns. Lessons learned from mining at depth and findings of research over the last decade are reviewed and applied to both civil and mining engineering problems.

-        Conventional and empirical design methods are reviewed and the effect of ground variability is explored. The ground reaction concept and design criteria are reviewed and explored during hands-on tutorial session.

- - - Coffee break - - -

Part 1: Ground characterization

10:20 - 12:00 Sessions 2 - Site Characterization I - In situ stress

-        Stress heterogeneity and geological structures

-        Characterizing in situ stress domains with measurements and field observations

-        Role of convergence measurements in characterizing a rock mass

- - - Lunch - - -

13:15 - 15:00 Session 3 - Site Characterization II - Rock mass properties

-        Rock classification are reviewed and limitations of empirical systems are explored

-        Dealing with variability - Tumbler Ridge Tunnel Case study

-        Using 3D software to develop geological models with Engineering Numbers; Block Modelling Techniques to extrapolate between boreholes:

- - - Coffee break - - -

15:30-16:15 Session 4 - Case Study I–– Rock classification (GSI) for Cavern Design in Japan - Dr. M. Cai, MIRARCO

-        the Geological Strength Index (GSI) is developed and compared to other classification systems

-        Quantification of Rock classification The Geological Strength Index; historical development; its limitations; quantification of block size and joint condition rating

16:15-16:45 Sessions 5 - Case study II - Donkin-Morien Tunnel

-        This case study is introduced as a base case for the tutorial sessions

16:45-18:30 Tutorial Session 1 - Influence of rock characteristics on tunnel deformations - F. Suorineni and P.K. Kaiser

-        Objective: to assess sensitivity of predicted deformations and extent of instability using our best estimate of the rock mass parameters and numerical tools. Software:  RocSupport (Deterministic and Probabilistic) and Phase2 with PEM (Tutorial 2)

 

Day 2 - November 14, 2002

Part 2: Excavations in highly stressed brittle rock

8:30-9:15 Sessions 6 - Site Characterization III - Brittle rock properties

-        Intact Rock Characterization

-        The effect of sample disturbance

9:15 - 10:00 Session 7: Brittle Failure I - rock failure

-        Understanding brittle failure is understanding damage initiation, propagation and coalescence

- - - Coffee break - - -

10:20 - 12:00 Session 8: Brittle Failure I - rock failure in situ

-        spalling limit and bi-linear failure envelop and brittleness index

-        VIDEO of brittle rock failure at URL

- - - Lunch - - -

13:00 - 14:00 Session 9: Brittle Failure II - failure of excavations

-        Underground Works in Hard Rock Tunnelling and Mining

-        Brittle Hoek-Brown parameters for predicting the depth of brittle failure around excavations

- - - Coffee break - - -

14:20 - 15:30 Session 10: Case studies III - Examples of Shaft, Tunnel and Pillar Stability Problems

-        Shafts, tunnels and stopes in hard rock

-        Tunnel in weak, brittle rocks (Mont Terri (Nagra, Switzerland)

-        Pillars in massive, moderately jointed rock

15:30-16:15 VRL - Sessions 11 - Integration of geology, complex excavation geometries and stress for risk assessment

-        Application of concepts developed in this course for risk assessment will be demonstrated on complex underground structures in Laurentian University's virtual reality Mining Exploratorium. A newly developed Drift at Risk (D @ R) tool, specifically developed by MIRARCO for the Mining Exploratorium, will be introduced and utilized to explore the interaction of geological, stress and geometric factors.

-        Integrating brittle behaviour modelling into VR for risk / hazard assessment (overbreak/dilution; drift stability - depth of failure and wedge viability)

16:30 - 17:30 Engineering Seminar - Recent developments in ground support – Rocky Wu (Mansour Mining) and Brad Simser (Noranda)

17:30 - 18:30 Tutorial Session 2: Brittle failure sensitivity to rock characteristics

-        Explore sensitivity of depth of failure to GSI assumptions

-        Intro to Phase2 for Day 3; Start Tutorial

Day 3 - November 15, 2002

Selected tunnelling topics and case studies

8:00 - 9:00 Session 12 - Tunnel excavation in brittle rock and case study of Toulnustouc Tunnel (Quebec) - Dany Gaudreault and Dan Lemieux - Sandvic/Tamrock

9:00 - 10:00 Session 13 - (Practical) Constraints in current practices affecting development rates in hard rock underground mining - Fidelis Suorineni - MIRARCO

--- Coffee break ---

10:00 - 11:00 Session 14 - Application of Wedge Analysis Techniques to Tunnel Support Design Practical) - Mark Diederichs (Queen's University) and John Henning (MIRARCO)

Part 3: Rockbursts - Violent brittle failure and implications of brittle failure on Support Design

-        Summary of Canadian Rockburst Support Handbook (Ch.1 - Introduction; Ch.3 - Support Design Methodology)

-        VIDEO of impact loading of bolts and shotcrete

11:00 - 12:30 Session 15: Rockbursts

-        Lessons Learned for Deep Tunnelling

-        Rockburst phenomena and types

-        Strainbursts - prediction (SRF); relative stiffness concept and sensitivity

-        Control of rockburst damage; destress and support

--- Lunch ---

13:30 - 14:00 Session 16 - Application of Yielding Bolts in Rockbursting Ground - Paul Germain - Atlas Copco

14:00 - 15:00 Sessions 17 - Deformations in brittle rock and implications for support selection

-        Rock mass bulking - effect of support methods on bulking

-        Support principals in bulking roc; Deformation compatibility - e.g. use of pre-reinforcement and SC near face

-        The role of Shotcrete in hard rock mines

-        Violent - hold, retain, reinforce; yielding support to dissipate energy à VIDEO from SA; SC impact and blast experiments

--- Coffee break ---

15:30 - 16:00 Sessions 18 - Lessons from TBM driven tunnel at depth - Furka and Lötschberg Tunnel (Switzerland)

-        Furka tunnel (Switzerland); Introduction to Tutorial 3

-        Tunnel face deformations in brittle rock and implications for TBM selection

16:00 - 17:30 Tutorial Session 3: Brittle failure simulation and sensitivity to rock characteristics – P.K. Kaiser/F. Suorineni

-        explore difference between H&B and brittle H&B

-        use Phase2 to get DoF (damage initiation and spalling limit)

-        sensitivity of DoF to GSI assumptions; demonstrate that putting numbers to geology is critical!

-        Linear vs non-linear modelling