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The Future for Rock Mechanics
and Rock Engineering
John A Hudson
Lecture 14
International Society for Rock Mechanics (ISRM)
Paper given at the 12th ISRM Congress, Beijing, Oct. 2011
The Next 50 Years of the ISRM and
Anticipated Future Progress
in Rock Mechanics
John A Hudson
ISRM President 2007 2011
Imperial College of Science, Technology and Medicine, London, UK
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This presentation on the 50-year anticipated future
of the ISRM and rock mechanics forms part of the
ISRM 50-year anniversary celebrations and
complements the preceding paper by E T Brown on
the previous 50 years of the ISRM.
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I will use two methods to predict the future of
the ISRM and rock mechanics:
1. Using the past and present future
2. Blue skies thinking
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In the first approach, we adopt the approach of
Hippocrates over 2000 years ago:
“Consider the past,
diagnose the present,
foretell the future.”
Hippocrates, 460-377 BC
温故知新
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F1
F2
F3
Fn
Fractures
Intact rock
Boundary
conditions
Excavation
Water flow
• Geology
• Rock stress
• Intact rock
• Fractures
• Rock mass properties
• Water flow
• Modelling
• Support
• Excavation
Some of the component subjects in rock
mechanics and rock engineering:
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Geology
There will be much more integration of geological features
into the modelling that supports rock engineering
designin order to make the modelling more realistic.
F1
F2
F3
Fn
Fractures
Intact rock
Boundary
conditions
Excavation
Water flow
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Rock Stress
There will be a much better understanding of the rock stress
distribution at a sitewhich we don’t always have currently.
F1
F2
F3
Fn
Fractures
Intact rock
Boundary
conditions
Excavation
Water flow
150 m depth, from Valli, Hakala and Kuula
(2011)
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• Tectonic scale and
regional stresses
• Site scale
• Excavation scale
• Borehole/measurement scale
• Microscopic scale
Different scales
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Fractures
Considerable work has already been done on the
geometrical and mechanical properties of fractures, but
much more is required.
Porteau Bluff on
Highway 99
North of Vancouver,
Canada
F1
F2
F3
Fn
Fractures
Intact rock
Boundary
conditions
Excavation
Water flow
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Rock mass properties
Similarly, we now have a good
understanding of estimating the
mechanical properties of rock
masses but,
in the future, there will also be
more emphasis on the influence
of fractures, inhomogeneity and
anisotropy aspects.
F1
F2
F3
Fn
Fractures
Intact rock
Boundary
conditions
Excavation
Water flow
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Water flow
Characterising and predicting water flow through a
fractured rock mass is not easy. Considerable progress
has been made, but much more work will be done in the
future.
F1
F2
F3
Fn
Fractures
Intact rock
Boundary
conditions
Excavation
Water flow
Mountsorrel granodiorite quarry, UK
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Modelling
This has developed extensively in the last 50 years
and will continue to do so in the next 50 years.
0
5
10
15
20
25
30
35
40
0 0.5 1 1.5 2
Strain (0.001)
Str
es
s (
MP
a)
H/W=3
H/W=1.5
H/W=1
H/W=0.67
H/W=0.5
H/W=3 H/W=1.5 H/W=1 H/W=2 H/W=0.5
Modelled using the RFPA code : Chun’an Tang et al.
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Support/Reinforcement
This has developed extensively in the last 50 yearsand
will continue to do so in the next 50 years.
It is difficult to see how support
can be significantly improved:
there are already good
techniques for holding the rock
back and for reinforcing it.
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Excavation
Mechanised excavation has been
a major breakthrough, but there is
still huge potential…
Robbins machine, Kielder Tunnel, UK, 1970s
Energy input
Time
Blasting: large amounts of energy input at widely spaced intervals
TBM: smaller amounts of energy input essentially constantly
Increasing the input energy would enable much faster penetration and advance rates
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Blue Skies
The two methods being used to predict the future of
the ISRM and rock mechanics are
1. Using the past and present future, and
2. Blue skies thinking.
So let’s now try Blue Skies…
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Growth in computing power
Next 50-100 years
50 years from now
All human brains
One human brain One mouse brain
One insect brain
Now
Ca
lcu
latio
ns p
er
se
co
nd
pe
r $
10
00
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It is now recognised that
Geological-Thermal-Hydrological-
Mechanical-Chemical-Engineering modelling
is required to fully understand the mechanisms
that occur in the rock mass.
Geological: site geometry, lithology, fractures
Thermal: heat loads, heat flow
Hydrological: water pressures, water flow
Mechanical: rock stress, stiffness, strength
Chemical: water chemistry, swelling rocks
Engineering: effects of excavation
Hopefully, we will have a fully-coupled model…
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What will happen to books?
Microsoft have announced that they will make 25 million
pages of books and documents available from the British
Library online and free of charge.
Google Print – same things for US libraries…
…and so we will all use the Internet.
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Publishing – Information communication
Computers will compile papers
about the cumulative advances
in rock mechanics using all the
papers published each year.
If computers become authors, how should they be identified,
or identify themselves?
Will we be able to tell if the author is human or a computer?
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Computer design of rock engineering facilities
At the moment, we as human engineers decide that we need
a rock engineering facility, then we make preparations,
operate a design model, evaluate the consequences, etc. Is
it possible that all this could be computerised one day?
Could the computer decide what engineering facilities are
required, then indicate what site investigation is required,
then choose the most appropriate numerical model from its
library, and then decide on the optimal engineering design?
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Attendance at
conferences
It will be an option whether we attend a conference
physically or electronically.
Some people will wish to attend physically, but electronic
attendance will be preferred by many others.
This has many advantages, not least of which is that one
could attend many more conferences.
What about Short Courses like this one?!! 22
Summary of future trends in rock mechanics
and rock engineering
• Improved methods of accessing/collating information
• More emphasis on geophysical methods in SI
• More integration of subjects (e.g. GTHMCB)
• More international co-operation
• More use of neural network ‘intelligent’ computer
programs
• Larger, deeper and longer excavations
• Emphasis on ‘environmental’ aspects
• Increased rate of mechanised excavation
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Finally, what is likely to happen to the ISRM in the
next 50 years?
There are two major
possibilities:
Scenario A
It will continue to be
successful and expand
both in terms of
membership and scope
Scenario B
It will disband because all the
existing benefits will be
available to individuals
through the Internet
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But, we have to work together – no one person can have
sufficient knowledge to understand the whole system in detail.
Unfortunately, we tend to work in our own subject areas
(cf. geology, rock and soil mechanics).
British Prime Minister, David Cameron: “We’re all in this together.”
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Modelling approaches
Use of
pre-existing
standard
methods
Analytical
methods,
stress-based
Basic
numerical
methods, FEM,
BEM, DEM,
hybrid
Extended
numerical
methods,
fully-coupled
models
Precedent type
analyses and
modifications
Rock mass
classification,
RMR, Q, GSI
Database
expert
systems, &
other systems
approaches
Integrated
systems
approaches,
internet-based
Objective
Construction
Site
Invest-
igation
Level 1
1:1 mapping
Level 2
Not 1:1 mapping
Design based on forward analysis Design based on back analysis
Method A Method B Method C Method D
The future
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Are we able to create a computerised virtual model of a rock
mass with all the GTHMCBE elements and then model a virtual
underground research laboratory and conduct virtual
experiments? e.g. the influence of scale.
Real Virtual
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The future is the Internet, and maybe the Semantic Web
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The Semantic Web
(‘Semantic’: understanding the meaning of information)
A method of representing semantically structured
knowledge. It extends the network of hyper-linked human-
readable web pages by inserting machine-readable
metadata about pages and how they are related to each
other, enabling automated agents to access the Web more
intelligently and perform tasks on behalf of users.
Computers will be able to gather the data, and one day
soon be able to write papers!
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• Where do we obtain the input information for the
model?
• What is the balance between generic and specific
information?
• How do we incorporate ‘memory’ into the model?
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Incorporating Memory into Rock Mechanics Modelling
and Rock Engineering Design
John A Hudson
Department of Earth Science and Engineering, Imperial College,
London, UK
Xia-Ting Feng
Institute of Rock and Soil Mechanics, Chinese Academy of
Sciences, Wuhan, China
ISRM Commission on Rock Engineering Design Methodology
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Abstract: This paper addresses the problem of obtaining the
information to support rock mechanics modelling and rock
engineering design.
A large amount of relevant material exists worldwide on
previous rock parameter determinations, modelling
exercises, design work, and construction projects. However,
the information learnt from these activities is not easily
accessible and useable, i.e. there has been no attempt to
develop a ‘corporate memory’ system for rock mechanics
and rock engineering.
A structure for such a system is outlined comprising tables of
intact and rock mass properties, libraries of standard and
case example modelling solutions, and libraries of design
and construction case examples. The procedure for initial
implementation of the memory system under the aegis of the
ISRM is described.
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Objective
Method A
Lab a
nd f
ield
tests
Use of
pre-existing
standard
methods
Construction and monitoring
Design based on forward analysis Design based on back analysis
Precedent type
analyses and modifications
Analytical methods,
stress-based
Integrated systems
approaches, internet-based
Site investig
ation
Level 2 Not 1:1
mapping
Level 1 1:1 mapping
Method B Method C Method D
Basic numerical methods,
FEM, BEM, DEM, hybrid
Extended numerical methods,
fully-coupled models
Rock mass
classification
RMR, Q,
GSI, BQ
Database expert
systems,& other
systems approaches
What information do we need
to support these boxes?
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Declarative knowledge Procedural knowledge
Specific knowledge learnt from
experience and generic knowledge
abstracted from many experiences
Skills knowledge such as touch-typing,
operating a computer, recognising when
there is likely to be a roof fall
Episodic
knowledge
Semantic
knowledge
e.g. knowledge
derived from
observation of a
cavern roof fall
e.g. knowledge of
rock mechanics
terminology
and units
The structure of human memory
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A 'CORPORATE MEMORY' SYSTEM
FOR ROCK MECHANICS INFORMATION
ROCK PROPERTY
INFORMATION
CONSTRUCTION
EXPERIENCE
MODELLING
EXERCISES
LABOR-
ATORY
TESTING
IN SITU
TESTING
GENERIC
MOD-
ELLING
SPECIFIC
MOD-
ELLING
DESIGN
CASE
EXAMPLES
CONST-
UCTION
CASE
EXAMPLES
COHERENCY CONDITIONING OF THE MODULES ABOVE
SO THAT THE INFORMATION CAN BE USED DIRECTLY
TABLES OF
INTACT ROCK
PROP-
ERTIES
TABLES OF
ROCK MASS
PROP-
ERTIES
LIBRARY OF
STANDARD
MODELLING
SOLUTIONS
LIBRARY OF
CASE
EXAMPLE
MODELLING
SOLUTIONS
LIBRARY OF
DESIGN
CASE
EXAMPLES
LIBRARY OF
CONST-
RUCTION
CASE
EXAMPLES
INTERROGATION AND RETRIEVAL SYSTEM
The three main
components
The six main subjects
The six main sources
of information
The required system
Converting the
information into a
useable form
The required corporate
memory system
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End of Lecture 14
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