Abstract

Percussion drills used in mines expose workers to high noise levels (115 to 125 db(A)). Although this is one of the main occupational health and safety concerns in the sector, no satisfactory solution has yet been found, due to the complexity of the physical phenomena involved.

The research-oriented portion of this feasibility study, conducted in collaboration with manufacturers, users and health and safety specialists, resulted in the developement of analytical models of drill shaft behaviour, shaft excitation, and noise propagation. These theoretical models were validated using an experimental test bed capable of simulating conditions under which drill shafts are used. The main parameters influencing noise levels were identified and possible solutions tested during trials.

In the technology-oriented portion of the study, a prototype of low-noise drill shafts was produced. Although noise levels were 8 dB lower, the reliability of the prototype remains problematic. These reliability problems are related to specific operating conditions and may necessitate significant modification of currently available shafts, in collaboration with tool and drill specialists.