Year
2023
Season
Summer
Paper Type
Master's Thesis
College
College of Computing, Engineering & Construction
Degree Name
Master of Science in Civil Engineering (MSCE)
Department
Engineering
NACO controlled Corporate Body
University of North Florida. School of Engineering
First Advisor
Raphael Crowley, Ph.D., P.E
Second Advisor
Ryan Shamet, Ph.D.
Third Advisor
James Gelsleichter, Ph.D.
Department Chair
Alan Harris, Ph. D.
College Dean
William Klosermeyer, Ph.D.
Abstract
In recent years, the potential impact on marine organisms of sound waves generated by pile driving has become a growing concern. Previous research in this field has predominantly relied upon single-strike averages to analyze underwater sound data. However, it was unclear from these analyses if or how much attenuation may vary during typical pile drives. This study involved collecting sound data from multiple locations during a given pile driving operation at the same time and used these data to analyze sound decay from each hammer blow individually. In addition to this, computational fluid dynamics (CFD) was used to better understand the components that may influence attenuation variability. The results reveal that each hammer blow exhibits a unique sound decay curve characterized by a distinct sound attenuation coefficient. Interestingly, these coefficients demonstrate variability within a drive event. Several potential factors contributing to these variations are identified, including the type of pile, variation in geotechnical conditions, hammer cushion, pile cushion, and channel properties. However, despite the variability observed in attenuation coefficients from one blow to another, an apparent relationship was consistently observed between source-level and attenuation – thereby providing additional basis for a previously proposed empirical model for predicting underwater attenuation. This emphasizes the need for further research in establishing exactly whether source level influences sound attenuation or if mode stripping variation is governed by additional sound attenuation.
Suggested Citation
Mushi, Consolatha Constantine, "Analysis of Underwater Noise due to Pile Driving in Florida using Individual Hammer Blows" (2023). UNF Graduate Theses and Dissertations. 1205.
https://digitalcommons.unf.edu/etd/1205