Application of design analysis to solution generation: Hand-arm vibrations in foundation pile head removal in the construction industry

Impact power tools are still widely used by many professions. Users of these tools are exposed to high levels of both vibration and shock. Reported health effects due to hand-arm vibration are `hand-arm vibration syndrome' (HAVS) and bone and joint injuries and disorders. In the construction industry a case study was conducted on one specific activity: removing concrete from the head of foundation piles. Pile heads are removed to allow the reinforcement rods to be connected to the rest of the foundation. Factors determining the vibration exposure were measured and the type and size of other occupational hazards were assessed qualitatively. The results showed that there was excessive exposure to vibration from the widely used hand-operated pneumatic drill as well as high exposure to other occupational hazards. The age of the drill, the make, the working pressure and the presence of a buffer ring have measurable effects on the level of vibration. But these adjustments only have a limited effect on the total workload. Instead of an exposure-oriented solution the present workload requires source-oriented solutions, which are expected to be more effective. A systematic approach towards the generation of possible solutions was adopted following the individual steps of the `problem-solving cycle', in combination with the design analysis technique. Design analysis is a method which can generate different types of solutions resulting in a reduction of the various hazards to an acceptable level.