Workplace environmental conditions and innovative tunnel driving techniques: measurement and control

The paper refers on the results of a data collection on workplace environmental conditions at the faces of some Italian tunnels, where the primary drifting is carried out by means of High Energy Hydraulic Hammers (H.E.H.H.). Thanks to the substantial improvements in the machine size and efficiency, the use of H.E.H.H. has dramatically grown since some years in Italy, mainly due to the quite stringent Italian regulations on the use and transportation of explosives: as a consequence the blasting techniques can sometimes prove uneconomical. But at the work places some problems arise, mainly due to the exposure conditions of the workers to noise and airborne particulates, since, to win the same quantity of rock won by traditional drilling and blasting techniques, the H.E.H.H. machine must work longer than a multiple arm boomer. Moreover, it is a common practice to carry on the mucking operations together with the H.E.H.H. machine working. As a consequence, the resulting overall environmental pollution at the face can rise to concerning values. The paper summarizes some of the possible techniques suitable both to reduce the pollutants production and to lower the exposure of workers, with special reference to the result of the research work which is at present carried on by the machine producers.