This paper describes open pit studies where blasting damage introduced in the remaining rock has been investigated. Results from two open pit mines are described and discussed. Parallel performed laboratory experiments, where simulated blasting damage has been introduced into samples before shear strength testing took place, are also reviewed. These studies are tied together in order to throw some light upon how the blasting damage influences the slope stability.
A mathematical model is also described which will make it possible to optimize the blast design for a specified damage zone in the rock mass.
Design of open pit slope angles is becoming more and more important as the mining depths of
open pits continuously increase. Small changes in the overall pit slope angle have large
consequences on the overall economy of the mining operation. A case in particular is the Aitik
open pit mine in northern Sweden, which currently faces the design of the overall slope angles
for continued mining toward a depth of around 500 meters. This report constitutes the first
phase in a research project aimed at developing design methods for large scale pit slopes. In
this report, the stability and design of large scale pit slopes in open pit mining is reviewed, with
special reference to slopes in hard, jointed, rocks, similar to the rock types found at the Aitik
mine. The review covers the mechanics of pit slopes, existing design methods for large scale
slopes, remedial measures and mining strategy to cope with slope failures, and a compilation
of case studies from open pits worldwide. Finally, suggestions for future research in this area