Quo Vadis Tunnel Engineering?Predicting the Unpredictable

Z T Richard Bieniawski v. Preinl

Closing Lecture: World Tunnel Congress 2014, Iguassu Falls, Brazil

“The Illiterate of the 21st century will not be those who cannot read and write, but those who cannot

learn, unlearn and relearn”

Futurist Alvin

Toffler

Sir Alan Muir Wood:

"With so many congresses and colloquia and symposia taking place every year, I demand of the people that I send to attend:'bring me back just one and only one good idea which I can use and I will pay all of your travelling expenses plus throw in a bottle of wine'!"

Tunnel design methodologies

Education for new cadres of tunnel engineers and

planners

Site investigation expenditures needed for effective tunnel design and

construction

Publications about predictions

Emerging Methodologies and Principles of Tunnel Design

Procedures

“What creates problems for us are not the things we don’t know

but those we think we know for sure”

President Dwight Eisehower

Books about Tunnel Design Methodologies (1)

Books about Tunnel Design Methodologies (2)

9

From X.Feng and J. Hudson: Rock Engineering Design (2010)

The subject of Design Methodology is now experiencing and will continue to experience major developments in the future because of new capabilities provided by the use of computer programs that can model the rock behavior in new and more insightful ways.

The concept of

D E A:

Diseño Estructural

Activo

Celada et al, 2010

Eurocode 7: Geotechnical Design

12

In the spirit of Alan Muir Wood: Best idea #1

Be specific when describing the chosen tunnel design methodology and use it as

a check-list (similar to what a pilot does prior to take off)

to ensure that all aspects of the undertaking are incorporated.

Training Tunnel Engineers and Educating Planners/Owners

"Each modern profession worthy of its name requires three elements: Theory, Education and Practice.

The reason: they are needed to guarantee its capacity for renewal and development."

Philosopher Herbert Simon (1969)

14

Challenges before us:

•Challenge to educate new tunnel engineers and engineering geologists, both men and women;

•Challenge to educate non-technical persons involved in planning tunneling projects or administering underground projects.

15

In the spirit of Alan Muir Wood: Best idea #2

• If you are a professor or a teacher, take initiative at your institution of higher learning;

*If you are in the tunneling business, help secure funds for a new industrial course;

*If you are neither: write articles to the press and the media suggesting action for the benefit of the society.

*For all of us at this Congress: let us support the concept of "continuing education" for tunnel engineers and "short courses" for the non-technical tunnel planners and

administrators.

When is Enough sufficiently enough for Tunnel Site

Investigations?

"Not all experience is necessarily good. We must learn only the best practices –

those used most widely in the most successfully competitive firms"

John Dixon (1991)

18

In Tunnel Design Practice

note this current shortcoming:

Sophistication of numerical methods of analysis far exceeds

the levels of reliability of the input data on rock mass

properties from limited field testing

U.S. National Committee on Tunneling Technology, 1984:

Geotechnical Site Investigations for Underground Projects: Overview of Practice and Recommendations:

Expenditures for geotechnical site exploration should be 3%of estimated project cost; typical 1-2% levels are incompatible with the 12% costs paid out for disputes.

20

Lack of field testing: Plate jacking tests

21

How many remember using this in situ test ?

Large Flat Jack (LFJ) test

22

Other types of large in situ tests Tri-axial block test Mine pillar test

23

In the spirit of Alan Muir Wood: Best idea #3

We must ensure that sophistication of analytical

modeling matches the reliability of the input data on rock mass properties – best determined

from reliable field tests!

QuoVadis

TunnelEngineering

?

Tunnels for a Better Life

26

Predictions

• Something old

• Something new

In conclusion• We need: (1)

better implemented tunnel design methodologies, (2) better educated tunnel engineers, planners and administrators, and (3) better executed site characterization programs;

• In the spirit of Alan Muir Wood: What is that ONE best idea that you have acquired at this Congress?

• “An exciting future beckons for tunnel boring!”, as announced by The Economist

“Enthusiasm is the greatest asset in the world;

it beats money, and power, and

influence!”

Henri Chester

Muitíssimo obrigado pela boa atenção !