Recording of Evert Hoek lecture on development of the Geological Strength Index (GSI)

The British Geotechnical Association (BGA) is grateful to Steve Hencher, Emeritus Professor in Engineering Geology at the University of Leeds for sharing with us an interesting recording of a lecture by Evert Hoek, the eminent rock mechanics engineer and 1983 Rankine Lecturer.

Steve recently discovered an audiotape of an invited keynote by Evert Hoek at Leeds, dating from 1990. Brushing it off, it plays very well and is clear and to the point. Contacting Evert, Steve managed to locate/ make up a series of slides to fit with the lecture and the whole thing has been compiled into a movie by Sam Hencher at Chimney Deutschland studios in Berlin.

The movie can be found here on the Hencher Associates Limited website.

The lecture must be one of the earliest and best, setting-out the philosophy behind the Hoek-Brown strength index, for isotropic fractured rock masses, at the large scale. Since then that chart has morphed into the Geological Strength Index (GSI). The whole lecture makes very good sense and is wholly relevant. It is particularly interesting and poignant at the end, hearing Evert’s expression of frustration at having to introduce the “embarrassing” chart because of the lack of anything else. Steve asks the question, where are we now, almost 30 years on?