Interpretation of the results of mechanical rock properties testing with respect to mining methods

rock cutting resistance, which is a frequently neglected issue.
Investigations into the mechanical properties of the unmined rock
are carried out at the stage of works involving deposit identification
or mining method selection. The most frequently performed tests
include uniaxial compressive strength and, sometimes, mineability
of the unmined rock. The results of these tests are strongly
correlated with the direction in which they have been carried out.
Additionally, depending on the method of mining (cutting,
planning, drilling) and the site of sampling (sidewall, face), the
direction of cutting is usually inconsistent with the direction of
testing. In the article, the author has drawn attention to the
commonly applied directions of cutting and presented
recommendations on the direction of testing to be followed in
underground mining plants in order to properly determine the
unmined rock properties. The results of the author's research into a
hard coal mine, rock salt and sandstones, shales and dolomites,
conducted in three perpendicular directions have also been quoted.
Furthermore, the subject literature in this field has been reviewed,
and selected investigations presented. The research results confirm
that depending on the cutting direction, there may be considerable,
even fivefold differences in the value of mechanical properties.
Knowing the planned cutting direction and the direction of testing is
a necessary condition for interpreting the results in a proper way,
choosing a suitable mining technique, the type of tools and process
parameters, as well as achieving the projected efficiency and energy
consumption.