Keynote Lecture - Reflections On New Horizons In Rock Mechanics Design:Theory, Education And Practice

This Keynote Address has much significance for me and I would like to begin by thanking the Organizing Committee for their kind invitation, specifically Dr Abbas Majdi, Chairman of the Symposium and of the Iran National Society for Rock Mechanics, and Dr A. Ghazvinian, ISRM Vice-President for Asia. This special significance is for three reasons:

1. Firstly, some years ago, my best doctoral students came from Iran and today they are leaders in their fields. On a number of occasions they invited me to visit, and this occasion proved to be most tempting. So, I wish to thank my colleagues here Professor Mohammed Sadaghiani of the prestigious Sharif University of Technology and Managing Director Farzan Rafia of Kavoshgaran Consulting Engineers for remembering their old professor and for their warm hospitality. Secondly, with my wife Elizabeth, a historian and library scientist, we have always dreamed of visiting Iran and observing its great history and culture, ever since we studied Persian achievements as students - me in my native Poland and she in her homeland of Scotland. It is a special treat for us both to enjoy seeing the splendor of your 2,500 years of history. Finally, and significantly, after my 45 years in rock mechanics, in research, teaching and consulting, I have been somewhat on the sidelines for the past decade, concentrating on practical tunnel design and construction. Thus, this Symposium gives me an opportunity to take a fresh look at rock mechanics and its relevance in the past 10 years and - after some reflections - to ponder on new horizons for its future. And what better occasion to do so than at an ISRM function, an organization which I joined in 1963 and served as Vice-President in 1974–79; what better place for this address than in fascinating Iran at an Asian Conference, a region which has so many countries leading in rock mechanics activities? This will be my last Keynote Address, as I retire this year from public appearances, and hope to leave you with a few useful observations on my current experiences and some thoughts for the future of rock mechanics. In the process, please permit me to be a little bit philosophical about our field. As a professor, my lecturing concept is: When lots of material is being covered, to avoid confusion, just emphasize three select ideas, and if anyone retains just one of them, I will have succeeded! My hope today is that each one of you might remember just one - let's call it - a ‘worthy’ idea from this Keynote Address which might enhance your future rock mechanics activities. So, I will summarize them at the end of each main section.

A classic assumption in geophysics is that shear wave polarization and splitting occurs due to stress-aligned structure, previously considered to be stress-aligned microcracks. This structure is now more often considered to be a desi