Abstract
This paper provides an overview of a blast monitoring trial using DAS technology at KGHM’s McCreedy West mine in Sudbury, Ontario. Fiber optics cable was installed in two short boreholes underground and multiple development and production blasts were recorded using DAS. The objective was to evaluate the technology’s capability to recognize/assess blasting design parameters and blasting performance for both efficiency and safety.
In this paper two of the long hole production blasts are reviewed. Each production blast comprised shots with time delays of 200 ms down to 25 ms. In visual inspection, the continuous recording of DAS captures individual shots with clarity even at 25ms time spacing.
Further analysis of data outputs the strength of each shot in individual holes which provides insight into the performance of design, and enables improvements for future designs, while it also detects misfires. Numeric analysis including power spectrum density and seismic wave amplitudes was performed. The power spectrum graphs shows that the signal power associated with the blasts at different delays did not interfere with each other. The calculated amplitudes from the blasting in both boreholes also showed the coherency of the signal without any aliasing or interference for different delay rates.
The paper provides an overview of the system set up, blast design parameters, summary of results as well as learnings and recommendations for future enhanced blast monitoring systems using DAS.