Blast monitoring instrumentation and analysis techniques, with an emphasis on field applications

Abstract

Abstract Detailed monitoring on hundreds of single hole and multi-row blasts in full scale varying blast environments were completed for specific analyses using high-speed photography and/or videography, laser surveying, refraction seismographs, digital seismographs to measure ground vibration/airblast, fragmentation and jointing analysis systems, borehole inspection cameras, multi-channel recorders and continuous VOD instrumentation. The majority of field tests were instrumented with multi-instrumentation systems in order to generate the most meaningful interpretation of the results for use in blast design optimization. Very rarely was only one type of instrumentation system used on full scale tests because it would severely restrict the scope of information required to generate site-specific custom blast designs, (Chiappetta 1991). For example, those that promote a single piece of equipment such as a seismograph to measure a single disturbance point in all of space, and then attempt to use the result to redesign a blast for improving on fragmentation, select optimum delay intervals, advising on explosive selections and recommending general blast design parameters, etc. can be misleading. Likewise, redesigning a blast based strictly on high-speed photography results, and assuming that the explosives, detonators and primers performed perfectly in the production blast can also have grave consequences. Stand alone velocity of detonation data, if not coupled to information obtained from the other instrumentation systems can also be meaningless from a design standpoint, unless obvious explosive malfunctioning or performance is evident. The point here is that unless the data are reviewed collectively from all of the instrumentation systems, true blast design optimization might never be realized, and the resulting design could be flawed along with a false economic assessment. This paper outlines the field instrumentation systems used and the information obtained for use in blast optimization.