Prediction and Monitoring of Underwater Sound Levels from the Implosion of a Reinforced Concrete Bridge Pier

2017 ◽  
Vol 2628 (1) ◽  
pp. 47-57
Author(s):  
Paul R. Donavan ◽  
James Reyff ◽  
Carrie Janello
Keyword(s):  
San Francisco ◽  
Peak Pressure ◽  
Underwater Sound ◽  
Surface Reflection ◽  
Sound Exposure ◽  
Reinforced Concrete Bridge ◽  
Sound Levels ◽  
Exposure Levels ◽  
And Performance ◽  
Peak Pressures

After the completion of the new east span of the San Francisco–Oakland Bay Bridge in California, large concrete piers of the old span needed to be demolished. To consider using controlled blasting for this action, hydroacoustic levels were predicted and monitored with regard to specified fish and marine mammal criteria. The metrics included peak pressure and sound exposure levels at distances from 25 to more than 4,000 ft from the pier. For peak pressure, the measured levels were slightly higher than estimated, although for sound exposure levels, the measured levels were somewhat lower than estimated because of the effect of surface reflection. A blast attenuation system consisting of a wide bubble stream was used to minimize the hydroacoustic levels in the water surrounding the pier. The implosion event consisted of 588 individual charge detonations ranging from 35 to 21 lb (15.9 to 9.5 kg/delay) spaced 9 ms apart. Although there were 135 individual detonations of the larger 35-lb charges, the highest peak pressures varied in level by 10 to 15 dB during the course of the implosion. The methods for predicting the levels, measured results, analysis of data, and performance of the blast attenuation system are reviewed.

Measurement and Prediction of Sound Exposure Levels by University Wind Bands

2010 ◽  
Vol 25 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Kris Chesky
Keyword(s):  
Linear Regression Analysis ◽  
Critical Role ◽  
Significant Proportion ◽  
Sound Exposure ◽  
Sound Levels ◽  
Wind Bands ◽  
Exposure Levels ◽  
The Mean ◽  
Over Time

The purpose of this study was to determine sound exposure levels generated in two college wind bands. Dosimeter data from a large sample of ensemble-based instructional activities (n = 43) was collected over time and processed to assess associations with predictor variables that may be relevant to this context, including indicators of time spend at various intensity levels, maximum and peak sound levels, degree of variability of sound levels over time, and the percentage of time playing music. The mean dose per event for the entire sample was 109.5% and ranged from 53.8% to 166.9%. Results of linear regression analysis revealed that regressors accounted for a significant proportion of the variance in dose (F = 128.42, p < 0.000) and a statistically significant and very large (96% variance accounted for) contribution to the prediction of dose. Findings implicate the critical role of the instructor and teaching pedagogy.

Sound Levels in Classrooms and Effects on Self-Reported Mood among School Children

2003 ◽  
Vol 96 (3_suppl) ◽  
pp. 1289-1299 ◽  
Author(s):  
Pär Lundquist ◽  
Kjell Holmberg ◽  
Lage Burström ◽  
Ulf Landström
Keyword(s):  
School Children ◽  
Sound Level ◽  
Work Environments ◽  
Task Orientation ◽  
Sound Exposure ◽  
Recorded Sound ◽  
Sound Levels ◽  
Sound Environment ◽  
Exposure Levels ◽  
Lower Background

The principle of this field study is an investigation of recorded sound levels in 24 classrooms and relations between sound level measures and aspects of children's rated annoyance, task orientation, and inattentiveness. The background sound-exposure levels were distributed within the interval of 33–42 dB(A)eq and the activity sound level exposure ranged between 47–68 dB(A)eq. The recorded levels must be considered as high for work environments where steady concentration and undisturbed communication is essential. Results do not support the hypothesis that lower background-sound level and fewer students per class would improve the sound environment by generating a lower activity noise or the hypothesis that higher sound levels should increase annoyance and inattentiveness as well as deteriorate task orientation ratings.

A sound exposure level study near the Camden Sound area, Browse Basin

2011 ◽  
Vol 51 (2) ◽  
pp. 705
Author(s):  
Andrew Long ◽  
Alec Duncan ◽  
Amos Maggi ◽  
Jeremy Colman ◽  
Jens Wisløff ◽  
...  
Keyword(s):  
Sound Level ◽  
Seismic Survey ◽  
Exposure Level ◽  
Underwater Sound ◽  
Marine Animals ◽  
Worst Case ◽  
Sound Exposure ◽  
Sound Levels ◽  
Marine Seismic ◽  
Threshold Criteria

A common approach to environmental risk assessment when assessing the level of risk to marine animals during marine seismic surveys is to compare either measured or modelled estimates of underwater sound levels to a known sound level threshold criteria. Over the years, a number of measures have been used to calculate and characterise underwater sound thresholds, including: sound pressure level (SPL), a root mean square (RMS) calculation, and—more recently—sound exposure level (SEL). SEL was suggested in 2007 by an expert panel of researchers as an appropriate measure to reduce the risk of temporary threshold shift (TTS) occurring in marine animals. Petroleum Geo-Services (PGS) commissioned an SEL study in preparation for a large MultiClient 3D seismic survey planned for the environmentally sensitive Camden Sound area, Western Australia, in late 2010. The Centre for Marine Science and Technology (CMST) at Curtin University built a comprehensive bathymetric model of the Camden Sound area and used two seabed geoacoustic models, with sand/limestone—as worst case, most reflective—and silt—as best case, least reflective. Acoustic propagation modelling over the frequency range of 8–1 kHz was used to build 3D maps of sound levels throughout all areas relevant to the seismic survey. The CMST SEL modelling results were integrated with other airgun array and SEL modelling pursued by PGS, and represent part of a broader environmental management strategy by PGS. Discussion is also given to other variants of SEL modelling.

Sound Exposure Levels Experienced by University Wind Band Members

2009 ◽  
Vol 24 (2) ◽  
pp. 63-70
Author(s):  
Jennifer Stewart Walter
Keyword(s):  
Hearing Loss ◽  
Occupational Safety ◽  
Wind Band ◽  
Cumulative Effect ◽  
Noise Induced Hearing Loss ◽  
Sound Exposure ◽  
Sound Levels ◽  
Safety And Health ◽  
Exposure Levels ◽  
University Setting

The purpose of this study was 1) to examine the sound exposure of wind band members in a university setting during a week of typical rehearsals and 2) to assess whether that exposure changes depending on subjects' location within the rehearsal space. Because excessive sound exposure has a cumulative effect on the ear that can eventually lead to noise-induced hearing loss, it is important to determine whether university musicians are at risk. A 100% dose of sound is the maximum daily exposure recommended by the National Institute of Occupational Safety and Health (NIOSH) for preventing noise-induced hearing loss. Twenty-four of 46 subjects (52%) experienced one or more rehearsals with sound levels high enough to produce >100% doses, and 17 subjects experienced a mean daily dose of sound in excess of 100% as compared to the NIOSH standards. Implications and suggestions for further research are discussed.

scholarly journals Effects of exposure to pile-driving sounds on the lake sturgeon, Nile tilapia and hogchoker

2012 ◽  
Vol 279 (1748) ◽  
pp. 4705-4714 ◽  
Author(s):  
Michele B. Halvorsen ◽  
Brandon M. Casper ◽  
Frazer Matthews ◽  
Thomas J. Carlson ◽  
Arthur N. Popper
Keyword(s):  
Nile Tilapia ◽  
Lake Sturgeon ◽  
Pile Driving ◽  
Swim Bladder ◽  
Wave Tube ◽  
Sound Sources ◽  
Severe Injuries ◽  
Sound Exposure ◽  
Sound Levels ◽  
Exposure Levels

Pile-driving and other impulsive sound sources have the potential to injure or kill fishes. One mechanism that produces injuries is the rapid motion of the walls of the swim bladder as it repeatedly contacts nearby tissues. To further understand the involvement of the swim bladder in tissue damage, a specially designed wave tube was used to expose three species to pile-driving sounds. Species included lake sturgeon ( Acipenser fulvescens )—with an open (physostomous) swim bladder, Nile tilapia ( Oreochromis niloticus )—with a closed (physoclistous) swim bladder and the hogchoker ( Trinectes maculatus )—a flatfish without a swim bladder. There were no visible injuries in any of the exposed hogchokers, whereas a variety of injuries were observed in the lake sturgeon and Nile tilapia. At the loudest cumulative and single-strike sound exposure levels (SEL cum and SEL ss respectively), the Nile tilapia had the highest total injuries and the most severe injuries per fish. As exposure levels decreased, the number and severity of injuries were more similar between the two species. These results suggest that the presence and type of swim bladder correlated with injury at higher sound levels, while the extent of injury at lower sound levels was similar for both kinds of swim bladders.

scholarly journals Explosives Use in Decommissioning – Guide for Assessment of Risk (EDGAR): II Determination of Sound Exposure Levels for Open Water Blasts and Severance of Conductors and Piles from Below the Seabed

2021 ◽  
Author(s):  
Alison Brand
Keyword(s):  
Marine Mammals ◽  
Oil And Gas ◽  
Total Error ◽  
Open Water ◽  
Noise Model ◽  
Underwater Sound ◽  
Sound Exposure ◽  
The Us ◽  
Exposure Levels

A simple underwater noise model suitable for use with explosive severance of well conductors and piles during the decommissioning of oil and gas subsea structures is introduced and evaluated against data from five projects in the US. This study focuses on a novel model for the determination of sound exposure levels. The model has been developed to enable determination of impact areas for marine mammals and fish. Simulated received underwater sound exposure levels were significantly correlated with measurements for all scenarios. The maximum total error achieved between simulations and measurements was 2.6%, suggesting that predictions are accurate to within 3% of the average measurement. A low relative bias was observed in the simulations when compared to measured values, suggesting only a small systematic underestimate (&le; 0.5% of average measurement) for most severance operations and a small overestimate (0.14%) for open water blasts.

scholarly journals Underwater sound levels in the Canadian Arctic, 2014–2019

2021 ◽  
Vol 168 ◽  
pp. 112437
Author(s):  
William D. Halliday ◽  
David Barclay ◽  
Amanda N. Barkley ◽  
Emmanuelle Cook ◽  
Jackie Dawson ◽  
...  
Keyword(s):  
Canadian Arctic ◽  
Underwater Sound ◽  
Sound Levels

Form as Weapon: the Political Function of Song in Urban Zimbabwean Theatre

2000 ◽  
Vol 16 (2) ◽  
pp. 148-154
Author(s):  
Martin Rohmer
Keyword(s):  
San Francisco ◽  
The Political ◽  
Political Protest ◽  
Colonial Rule ◽  
Cultural Management ◽  
Political Function ◽  
Humboldt University ◽  
Forced Labour ◽  
And Performance ◽  
The University

In Zimbabwean society, what may not be spoken sometimes becomes acceptable in song – whether to avoid social taboos and enable a wife to complain against her mother-in-law, or in broadening the boundaries of political protest. In this article, Martin Rohmer looks back to the ways in which song enabled forms of protest against forced labour and other aspects of colonial rule – in times of outward compliance as well as of direct struggle – and considers how urban theatre groups in independent Zimbabwe have adapted the tradition to their own, contemporary ends. Martin Rohmer spent almost two years studying Zimbabwean theatre when a research assistant at the University of Bayreuth, and completed his doctorate on Theatre and Performance in Zimbabwe at the Humboldt University, Berlin, in 1997. Since then he has been working in the field of cultural management for the Young Artists' Festival in Bayreuth. The present paper was first presented at the Annual Meeting of the African Studies Association in San Francisco in November 1996.

Aircraft noise-induced awakenings are more reasonably predicted from relative than from absolute sound exposure levels

2013 ◽  
Vol 134 (5) ◽  
pp. 3645-3653 ◽  
Author(s):  
Sanford Fidell ◽  
Barbara Tabachnick ◽  
Vincent Mestre ◽  
Linda Fidell
Keyword(s):  
Aircraft Noise ◽  
Sound Exposure ◽  
Exposure Levels

Application of the method of dimensional analysis in laser-shock-wave processing of titanium alloys with shape memory

2021 ◽  
pp. 66-72
Author(s):  
Keyword(s):  
Shock Wave ◽  
Finite Element ◽  
Plastic Zone ◽  
Shape Memory ◽  
Dimensional Analysis ◽  
Peak Pressure ◽  
Laser Shock ◽  
Zone Depth ◽  
Peak Pressures ◽  
Laser Shock Wave

The processes of laser-shock-wave processing of NiTi alloys with shape memory effect are investigated by the methods of dimensional analysis and finite element modeling. The dependences of the depth of the plastic zone on the peak pressure in the shock wave and the duration of the laser pulse are obtained at different peak pressures. Keywords: shape memory alloys, laser-shock-wave processing, dimensional analysis, residual stresses, plastic zone depth. [email protected]

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