INFLUENCE OF GEOLOGICAL DISCONTINUITIES UPON FRAGMENTATION BY BLASTING

Discontinuities are an integral part of the rock masses and pose special problems in blasting operations in mining and civil industries resulting in high excavation cost due to underbreak and overbreak problems. Experience has shown that the excessive blast damage to the perimeters of underground and surface excavations due to presence of discontinuities can be controlled in an appreciable manner by careful blast design keeping in view the discontinuities present in the rock masses. This paper reviews the findings of different researchers on the influence of geological discontinuities upon rock fragmentation by blasting and discusses some methods proposed to control the overbreak problems in excavation.