Air Blast and Ground Vibrations Due to Blasting at Gevra Project of South Eastern Coalfields Ltd in India

Abstract

Blasting in opencast mining is a vital activity and is the source of environmental and socio-economic problems. The annoying circumstances as a result of impacts due to blasting many times lead to unfavourable mining operations, confrontation and sometimes even litigation. Due to the shortage of land and difficulties in land acquisition, blasting operations at Gevra and Dipka opencast projects of South Eastern Coalfields Limited (SECL) were done close to the buildings and surface structures. Peak particle velocity (PPV) and air over pressure levels during blasting were monitored to avoid annoyance and prevent damage to surface structures. Blasting by conventional techniques using detonating fuse produced ground vibrations and air blast noise greater than the desired limits. Properly planned blast design and blast parameters, like spacing, burden, depth of hole, stemming, etc. as well as adoption of a shock tube initiation system reduced the ground vibrations and air blast noise. A relationship was established between the blast parameters, which can be used in conditions similar to those prevailing at Gevra project.