Elimination of ground vibrations and fly rock: A case study of an opencast mine

Abstract

At the JK Opencast Project, studies were made to eliminate the problems of ground vibrations and fly rock. Ground vibrations were studied with blast vibration monitors. Changes in the initiation pattern from earlier V-pattern to the straight-line pattern and reduction in charge weight per delay, resulted in elimination of ground vibrations problem. Adoption of straightrow pattern of initiation with a clear free face, introduction of air deck, bottom initiation of blastholes and muffling of individual holes with wire meshes overlain by sand bags of 25 kg resulted in complete elimination of fly rock.