Attenuation of pile driving noise using a double walled sound shield

Jan. 31, 2015

AUTHORS

Per G. Reinhall and Peter H. Dahl

ABSTRACT

Pile driving in water produces high sound levels in underwater environments. The associated pressures are known to produce deleterious effects on both fish and marine mammals. We present an evaluation of the effectiveness of surrounding the pile with a double walled sound shield to decrease impact pile driving noise. Four 32 m long, 76 cm diameter piles were driven 14 m into the sediment with a vibratory hammer. A double walled sound shield was then installed around the pile, and the pile was impact driven another 3 m while soundmeasurements were obtained. The last 0.3 m was driven with the sound shield removed, and data were collected for the untreated pile. The sound field obtained by finite element analysis is shown to agree well with measure data. The effectiveness of the sound shield is found to be limited by the fact that an upward moving Machwave is produced in the sediment after the first reflection of the deformation wave against the bottom end of the pile. The sound reduction obtained through the use of the sound shield, as measured 10 meters away from the pile, is shown to be approximately 12dB dB re 1 μPa.

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http://scitation.aip.org/content/asa/journal/jasa/132/3/10.1121/1.4755475

"Reinhall Piles provide a much needed and environmentally beneficial innovation in the arena of marine construction. This technology can significantly reduce the noise mitigation effort and setup time, and is far more protective."
Michael Spillane, PE, President Herrera Environmental Associates

Hear the difference

Recorded from hydrophone deployed at 10m during subscale testing of 8" steel piles in Seattle, Washington in 2013.

You are hearing 4 strikes of a standard pile followed by 4 strikes of a Reinhall Pile™. Notice the difference.