Salmoni Alan, Cann Adam, Gillin Kent
School of Kinesiology, University of Western Ontario, London, Ontario, Canada.
Work. 2010;35(1):63-75. doi: 10.3233/WOR-2010-0958.
It is often difficult to access a large sample of vehicles in various work environments to evaluate worker exposure to vibration such as in construction and mining. Thus the main purpose of the present research was to test vibration exposure in a relatively large number of earth scrapers. The second aim was to assess vibration exposure values on seat transmissibility.
33earth scrapers were assessed for both exposure to whole-body vibration and seat transmissibility.
Two triaxial accelerometers, one placed on the seat and one on the floor directly below the seat, were used to gather whole-body vibration values (a(w)). Each machine was tested for a minimum of three complete work cycles: idling, scraping, travelling full, dumping, travelling empty back to the scrape site.
Results showed that idling and scraping produced low levels of vibration when compared to travelling and dumping. Second, when the a(w) values were compared to the EU safety standards for an eight hour work day, the data (z axis) exceeded the exposure action value (0.5 m/s2) in all machines, and the exposure limit value (1.15 m/s2) in some. Implications; Operators of the scrapers were being exposed to unsafe levels of whole-body vibration. When the seats were assessed to see whether they were attenuating operator exposure to vibration, many of the seat effective amplitude transmissibility (SEAT) values exceeded 1.0. This meant that some of the seats were actually amplifying the vibration present at the floor, particularly in the y axis.
Travelways should be kept smooth, operating speeds reduced, and new seats, effective in all three axes, designed.
在建筑和采矿等各种工作环境中，通常很难获取大量车辆样本以评估工人接触振动的情况。因此，本研究的主要目的是在相对大量的土方工程车辆中测试振动暴露情况。第二个目的是评估座椅传递率的振动暴露值。
对33辆土方工程车辆的全身振动暴露和座椅传递率进行了评估。
使用两个三轴加速度计，一个放置在座椅上，另一个放置在座椅正下方的地板上，以收集全身振动值（a(w)）。每台机器至少进行三个完整的工作循环测试：空转、铲土、满载行驶、卸料、空载返回铲土现场。
结果表明，与行驶和卸料相比，空转和铲土产生的振动水平较低。其次，将a(w)值与欧盟八小时工作日的安全标准进行比较时，所有机器的数据（z轴）均超过了暴露行动值（0.5米/秒²），部分机器超过了暴露限值（1.15米/秒²）。启示：土方工程车辆操作员正暴露于不安全水平的全身振动中。在评估座椅是否能减轻操作员接触振动的情况时，许多座椅有效振幅传递率（SEAT）值超过了1.0。这意味着一些座椅实际上放大了地板上的振动，尤其是在y轴上。
应保持行车道平整，降低运行速度，并设计在所有三个轴向上均有效的新座椅。
