Division of Environmental Sciences, Bureau of Ocean Energy Management, Sterling, Virginia 20166, USA.
Marine Mammal Commission, Bethesda, Maryland 20814, USA.
J Acoust Soc Am. 2022 Jan;151(1):310. doi: 10.1121/10.0009272.
Sound generated by pile installation using a down-the-hole (DTH) hammer is not well documented and differs in character from sound generated by conventional impact and vibratory pile driving. This paper describes underwater acoustic characteristics from DTH pile drilling during the installation of 0.84-m shafts within 1.22-m steel piles in Ketchikan, Alaska. The median single-strike sound exposure levels were 138 and 142 dB re 1 μPas at 10 m for each of the two piles, with cumulative sound exposure levels of 185 and 193 dB re 1 μPas at 10 m, respectively. The sound levels measured at Ketchikan were significantly lower than previous studies, and the sound was determined to be non-impulsive in this study as compared to impulsive in previous studies. These differences likely result from the DTH hammer not making direct contact with the pile, as had been the case in previous studies. Therefore, we suggest using the term DTH pile drilling to distinguish from DTH pile driving when the hammer strikes the pile. Further research is needed to investigate DTH piling techniques and associated sound-generating mechanisms and to differentiate the various types of sound emitted, which has important implications for the underwater sound regulatory community.
使用潜孔锤（DTH）进行打桩产生的噪音没有得到很好的记录，其特性与传统冲击式和振动式打桩产生的噪音不同。本文描述了在阿拉斯加凯奇坎，将 0.84 米的轴安装在 1.22 米的钢桩内时，DTH 桩钻孔的水下声学特性。两根桩的每根桩在 10 米处的单次冲击声暴露水平中值分别为 138 和 142 dB ，相应的 10 米处累积声暴露水平分别为 185 和 193 dB 。凯奇坎测量的声级明显低于以往的研究，并且与以往研究中的脉冲性相比，本研究中确定声音是非脉冲性的。这些差异可能是由于潜孔锤没有像以往的研究那样直接接触桩造成的。因此，当锤子撞击桩时，我们建议使用 DTH 桩钻孔一词来区分 DTH 桩驱动。需要进一步研究 DTH 打桩技术和相关的发声机制，并区分发出的各种类型的声音，这对水下声音监管社区具有重要意义。
