Quebec-based occupational health and safety research firm IRSST has published its evaluation of whole body vibration (WBV) exposure of workers, particularly those operating soil compactors. In its report, the IRSST found most compactors used in Quebec lack suspension seats, which are vital for limiting workers' exposure to WBV.
The IRSST study investigated vibration properties and operator exposure to WBV of single-drum vibratory soil compactors — which are widely used for compacting soils and road building — through measurements, and presents spectral classes of vibration that could be applied for identifying desired interventions.
Two test series were undertaken to characterize the mechanical vibration properties of the vehicles and vibration exposure of the operators. The first test series was performed on a test track under controlled conditions, namely, the speed, the amplitude of vibration due to the rotating mass integrated within the drum and the soil properties.
The objective was to determine the vibration behaviours of the vehicles in terms of dominant ride frequencies and probable vibration modes. The second test series was undertaken at two different worksites in Québec in order to quantify and assess the WBV exposure under typical working conditions.
The results of the study suggest that the use of an adequately tuned suspension seat would be vital for limiting the exposure below the action value, particularly for the 10-ton machine, which is most representative of the compactors used in Quebec, the IRSST said. It was observed that most of the compactors used in Quebec do not employ a suspension at the seat and the cabin suspension is limited only to rubber mounts.
Further efforts are also recommended to examine the design of suspension seats used in the newer vehicles and their actual adjustment in the field to limit the transmitted vibration. Further efforts in identifying optimal cabin mounts are also desirable and recommended for limiting the WBV exposure, the IRSST said.
To download the report go to the IRSST website.