Noise emitted by drop hammer piling machine and workers' noise exposure

Abstract

Hammer driven piling machine is the typical piling equipment in Malaysia, according to previous research on piling activities more than a decade ago more than an average of 90 dBA was recorded during the occurrences of piling activities at a common construction site that disturbs the neighbourhood. However, the direct effect of piling activities are the operator and signal man. Up to date there is no detail data about the noise exposure level experienced by these workers from these activities in order to facilitate the noise management in construction site. In this paper the propagation of sound level data on the recent hammer driven piling machines and noise exposure to operators and signal man were acquired and evaluated. Sound data were obtained by using sound level meter type 2 while noise exposure of workers by using noise dosimeter. Data were taken from six sites with piling machine age bellow 10 years, 7ton Hammer, 300mm Spun Pile and Laterite type of soil. It was obtained that piling hammering noise level was found exceeds the permissible maximum noise level of 90 dBA as highlighted by FMR 1989 up to distance more than 4m from piling machine. With this result it directly affected the signalmens and this is confirmed by the reading of noise exposure of them exceeding the 90 dBA and more than 100% dose. From the analysis, clearly that the piling machine workers especially the signal man underestimate the impact of high impact pulsing sound level generated even at the softest soil condition. It is proposed that signal man must wear proper hearing protection device with Noise reduction rating (NRR) of 20-30 dBA.