The post-failure characteristics of rock. Pt 1: Intact and broken rock
Tim Grain JOSEPH,
A strain-softening constitutive relationship is
introduced that describes the post-failure
stress-strain curve for rock regardless of whether
the rock is intact or broken. The core of this
relationship is an "apparent friction" concept
that relates the post-failure apparent cohesive
and frictional characteristics of the rock to the
strain. The relationship can be determined for a
given rock via a series of tri-axial strength
tests establishing the peak strength and
corresponding strain for a range of confining
pressures, together with the determination of the
base angle of friction via a simple tilt test.
The postulates and assumptions used in deriving
this relationship are verified from results of
tri-axial tests on both intact and
Keywords:
Intact rock, Post-failure behaviour, Broken rock