A method for investigating the extent of rock bridges: FERM

Overview

The talk is based on the Manuel Rocha 2020 prize–winning thesis for the International Society for Rock Mechanics (ISRM) prepared by Dr Shang at the University of Leeds under the supervision of Professors Hencher and West.

Professor Hencher outlines the concept of “taking a hillside to pieces”, block-by-block, using non-blasting methods, to establish the extent of rock bridges. Such methods it is argued should allow the delineation of rock bridges, which can be linked to mass weathering classification and structural regime.

Dr Shang will present laboratory and field studies to test the tensile strength of rocks, showing examples of intact bedded sandstone and incipient discontinuities. He will then describe laboratory and field scale studies to open up incipient joints at two quarries, one at Dryrigg, near Horton-in-Ribblesdale, the other close to Leeds. Both tests identified rock bridge sections of intact rock, with much rougher surface texture compared to the incipient joint section.

Finally Professor Hencher will discuss the implications of this research as a tool to improve our understanding of rock slope stability and fluid flow through rock and hence, nuclear waste containment.