Exploiting ground effects for surface transport noise abatement

AbstractGrowing demand on transportation, road and railway networks has increased the risk of annoyance from these sources and the need to optimise noise mitigation. The potential traffic noise reduction arising from use of acoustically-soft surfaces and artificial roughness (0.3 m high or less) is explored through laboratory experiments, outdoor measurements at short and medium ranges and predictions. Although the applicability of ground treatments depends on the space usable for the noise abatement and the receiver position, replacing acousticallyhard ground by acoustically-soft ground without or with crops and introducing artificial roughness configurations could achieve noise reduction along surface transport corridors without breaking line of sight between source and receiver, thereby proving useful alternatives to noise barriers. A particularly successful roughness design has the form of a square lattice which is found to offer a similar insertion loss to regularly-spaced parallel wall arrays of the same height but twice the width. The lattice design has less dependence on azimuthal source-receiver angle than parallel wall configurations.

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Traffic Noise Mitigation Using Single and Double Barrier Caps of Different Shapes for an Extended Frequency Range

Applied Sciences ◽

10.3390/app10175746 ◽

2020 ◽

Vol 10 (17) ◽

pp. 5746 ◽

Cited By ~ 1

Author(s):

Domingo Pardo-Quiles ◽

José-Víctor Rodríguez ◽

Jose-Maria Molina-García-Pardo ◽

Leandro Juan-Llácer

Keyword(s):

Road Traffic ◽

Traffic Noise ◽

Noise Mitigation ◽

Noise Barriers ◽

Double Barrier ◽

Noise Abatement ◽

Extended Frequency ◽

Different Shapes ◽

The Aesthetic ◽

Insertion Losses

The primary function of noise barriers is to shield inhabitants of affected areas from excessive noise generated by road traffic. To enhance the performance of noise barriers while simultaneously adhering to height restrictions, the attachment of structures (caps) of different shapes to the tops of conventional screens can be considered. These caps can significantly impact the diffracted sound energy, thereby increasing the desired global acoustic losses. This work presents a comprehensive study of the acoustic performance of noise barriers with single and double attached caps of different shapes through a calculation of their insertion losses (IL). This study comprehensively addresses and compares different types, sizes, combinations, and numbers of noise barrier caps for different scenarios (including sloping and absorbent grounds) and sources (“car” and “ambulance”) for an extended frequency band up to 10 kHz. To the best of the authors’ knowledge, this is a range that has not previously been analyzed. A variety of different cap shapes were considered including cylinders, rectangles, trapezoids, and Y/T-shaped forms. To calculate the IL, an innovative and fast uniform theory of diffraction (UTD)-based method developed by the authors was applied in all simulations. The results showed that the Y-shaped single and double barrier caps were, in general, the most effective at increasing IL without raising the height of the barrier, thereby successfully managing the aesthetic impact. The results also showed how the consideration of sloping and absorbent floors could also contribute to improved noise abatement.

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Results of the 10-Year Arizona Quiet Pavement Pilot Program

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/03611981211005460 ◽

2021 ◽

pp. 036119812110054

Author(s):

Paul R. Donavan ◽

Carrie J. Janello

Keyword(s):

Traffic Noise ◽

Pilot Program ◽

Average Increase ◽

Portland Cement Concrete ◽

Noise Mitigation ◽

Noise Abatement ◽

Initial Reduction ◽

Type 3

In April 2003, the Arizona Department of Transportation (ADOT) initiated a Quiet Pavement Pilot Program in cooperation with the Federal Highway Administration (FHWA). Under this program, many freeway segments in the Phoenix metropolitan area with Portland Cement Concrete pavement surfaces received 25.4-mm thick asphalt rubber friction course overlays to reduce highway-related traffic noise. This pilot program represented the first time that pavement type was allowed as a noise mitigation strategy on federally funded projects. As part of this program, ADOT developed a 10-year research program with FHWA to evaluate the long-term acoustic performance of this noise mitigation approach. The final measurements were completed in 2015. The program was done with three types of measurements: Type 1 examined tire/pavement noise at the source at 115 milepost locations; Type 2 examined noise in residential neighborhoods near the freeways; and Type 3 evaluated noise using direct measures of traffic noise adjacent to the freeways. Sound absorption measurements were also made at specific sites at various times throughout the project. Type 1 measurements documented an average initial reduction of 8.7 dBA and an average increase of 0.5 dB/year. The Type 2 measurements revealed an average initial reduction of 5.2 dBA, whereas the Type 3 measurements showed an average initial reduction of 9.1 dBA and an average increase of 0.5 dB/year. The measured reductions were also compared with ADOT and FHWA noise abatement criteria.

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Noise Reduction by Using Composite Plate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.47-50.1229 ◽

2008 ◽

Vol 47-50 ◽

pp. 1229-1232

Author(s):

C.W. Chau ◽

Y.S. Choy ◽

Kin Tak Lau ◽

Yang Liu

Keyword(s):

Noise Reduction ◽

Carbon Fibers ◽

Side Branch ◽

Bending Stiffness ◽

Composite Panel ◽

Expansion Chamber ◽

Noise Abatement ◽

High Tension ◽

And Performance ◽

Very High

The plate silencer1 which consists of an expansion chamber with two side branch cavities covered by a light panel can achieve a desirable noise reduction in broadband theoretically. The concept is similar to drum silencer2. To attain optimal noise reduction, either the membrane should be of minimal weight while retaining very high tension or the panel should be kept with very high bending stiffness that is dependent on its geometry and mechanical properties. To achieve such goal, various kinds of composite system such as carbon fibers or aluminum were mounted on light core foam. A design of the composite panel which can provide a reduction in panel weight as well as enhance the bending stiffness, is introduced in this project. Predictions of the new model are to be compared with the normal foam plate in the aspects of noise reflection capability and performance of noise abatement apart from the material properties.

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Value for Money in Road Traffic Noise Abatement

Procedia - Social and Behavioral Sciences ◽

10.1016/j.sbspro.2012.06.1112 ◽

2012 ◽

Vol 48 ◽

pp. 1366-1374 ◽

Cited By ~ 2

Author(s):

Ingunn Milford ◽

Sigve J. Aasebo ◽

Kjell Strommer

Keyword(s):

Road Traffic ◽

Traffic Noise ◽

Road Traffic Noise ◽

Value For Money ◽

Noise Abatement

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Perception of Traffic Noise Barrier Effectiveness: Public Opinion Survey of Residents Living near I-71

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1601-08 ◽

1997 ◽

Vol 1601 (1) ◽

pp. 49-54 ◽

Cited By ~ 4

Author(s):

Lloyd A. Herman ◽

Michael A. Finney ◽

Craig M. Clum ◽

E.W. Pinckney

Keyword(s):

Public Opinion ◽

Traffic Noise ◽

Department Of Transportation ◽

Opinion Survey ◽

Noise Barriers ◽

Noise Abatement ◽

Public Controversy ◽

Public Opinion Survey ◽

Project Area ◽

Noise Barrier

The completion of the largest Ohio Department of Transportation traffic noise abatement project in 1995 was met with public controversy over the effectiveness of the noise barriers. A public opinion survey was designed to obtain the perceptions of the residents in the project area. In a departure from most surveys of traffic noise barrier effectiveness, the coverage was not limited to the first or second row of houses, but was extended to 800 m on each side of the roadway. It was found that the larger survey area was needed to avoid misleading conclusions. Overall perceptions of noise barrier effectiveness were found to vary with distance from the roadway and with noise barrier configuration.

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