CEN/TC 256/WG 40 - Noise barriers

This document specifies the laboratory method for measuring the airborne sound insulation performance of railway noise barriers in reverberant conditions. It covers the assessment of the intrinsic performance of noise barriers and related devices acting on airborne sound propagation that can reasonably be assembled inside the testing facility described in EN ISO 10140 2 and EN ISO 10140 4.
This method is not intended for the determination of the intrinsic characteristics of airborne sound insulation of noise barriers to be installed on railway in non-reverberant conditions.
All noise reducing devices different from noise barriers and related devices acting on airborne sound propagation, e.g. devices for attenuation of ground borne vibration and on board devices, are out of the scope of this document.

This document describes a test method for measuring a quantity representative of the intrinsic characteristics of sound absorption from railway noise barriers and related devices acting on airborne sound propagation, the sound reflection index RI, and then calculate a single-number rating for sound absorption from it.
The test method is intended for the following applications:
-   determination of the intrinsic characteristics of sound absorption of noise barriers and related devices acting on airborne sound propagation to be installed along railways, to be measured either on typical installations alongside railways or on a relevant sample section;
-   determination of the intrinsic characteristics of sound absorption of noise barriers and related devices acting on airborne sound propagation in actual use under direct sound field conditions;
-   comparison of design specifications with actual performance data after the completion of the construction work;
-   verification of the long-term performance of noise barriers and related devices acting on airborne sound propagation (with a repeated application of the method).
The test method is not intended for the following applications:
-   determination of the intrinsic characteristics of sound absorption of noise barriers and related devices acting on airborne sound propagation to be installed in reverberant conditions, e.g. inside tunnels or deep trenches.
Results for the sound reflection index are expressed as a function of frequency, in one-third octave bands, where possible, between 100 Hz and 5 kHz. If it is not possible to get valid measurements results over the whole frequency range indicated, the results are given in a restricted frequency range and the reasons of the restriction(s) are clearly reported.

This European Standard specifies the laboratory method for measuring the sound absorption performance of railway noise barriers and related devices acting on airborne sound propagation in reverberant conditions. It covers the assessment of the intrinsic sound absorption performance of devices that can reasonably be assembled inside the testing facility described in EN ISO 354.
This method is not intended for the determination of the intrinsic characteristics of sound absorption of noise barriers and related devices acting on airborne sound propagation to be installed on railways in non-reverberant conditions.
The test method in EN ISO 354 referred to in this European Standard excludes devices that act as weakly damped resonators. Some devices will depart significantly from these requirements and in these cases, care is needed in interpreting the results.

This document describes a test method for measuring a quantity representative of the intrinsic characteristics of airborne sound insulation for rail noise barriers and related devices: the sound insulation index.
The test method is intended for the following applications:
-   determination of the intrinsic characteristics of airborne sound insulation of noise barriers and related devices to be installed along railways, to be measured either on typical installations alongside railways or in laboratory conditions;
-   determination of the intrinsic characteristics of airborne sound insulation of noise barriers and related devices in actual use;
-   comparison of design specifications with actual performance data after the completion of the construction work;
-   verification of the long-term performance of noise barriers and related devices (with a repeated application of the method);
-   interactive design process of new products, including the formulation of installation manuals.
The test method is not intended for the determination of the intrinsic characteristics of airborne sound insulation of noise barriers and related devices to be installed in reverberant conditions, e.g. inside tunnels or deep trenches or under covers.
Results are expressed as a function of frequency in one-third octave bands, where possible, between 100 Hz and 5 kHz. If it is not possible to get valid measurement results over the whole frequency range indicated, the results need to be given in a restricted frequency range and the reasons for the restriction(s) need to be clearly reported.

This document specifies a normalized railway noise spectrum for the evaluation and assessment of the acoustic performance of devices designed to reduce airborne railway noise near railways.
All noise reducing devices different from noise barriers and related devices acting on airborne sound propagation, e.g. devices for attenuation of ground borne vibration and on board devices are outside of the scope of this document.

This document specifies a normalized railway noise spectrum for the evaluation and assessment of the acoustic performance of devices designed to reduce airborne railway noise near railways.
All noise reducing devices different from noise barriers and related devices acting on airborne sound propagation, e.g. devices for attenuation of ground borne vibration and on board devices are outside of the scope of this document.

This document describes the basic requirements for the verification of ultimate and serviceability limit states and the resistance to fatigue either of the noise barrier or its components by means of analytical methods and/or tests.
Analytical methods can be used for the determination of the characteristic values and design values.
Where sufficient information is not available, the analytical procedure can be combined with results from tests.
This document provides the following types of test procedures:
-   test on small samples for defining detail categories, which may not be covered by Eurocodes (verification procedure A);
-   test on a global element for defining the limit state against fatigue (verification procedure B);
-   full scale tests under a given representative loading (verification procedure C) to determine fatigue resistance of the noise barrier components for defined loading conditions; verification procedure C is given as alternative to verification procedures A and B.

This document applies only to noise barriers composed of posts as structural elements and panels as acoustic elements (fabricated for example from metal, timber, plastic or concrete panels). It also applies for acoustic claddings of existing walls and partial or total acoustic coverings of the rail track.
It is important that acoustic elements are tested together with the structural elements to represent the noise barrier as in the intended use.
This document provides criteria to verify railway noise barriers and related devices according to basic mechanical performance under standard conditions of exposure, irrespective of the materials used. A range of conditions and optional requirements is provided to allow for the wide diversity of practice within Europe. Individual aspects of performance are covered separately in the annexes.
This document provides test methods and criteria for the assessment of railway noise barriers with respect to their mechanical performance and stability under static loading.

This European Standard specifies requirements for assessing the working life and provides the relevant exposure conditions.
Standards of construction and any material tests conducted should provide evidence of resistance to specified conditions selected from the following:
I.   Chemical Agents   Location
dependent
II.   De-icing salt   Location/climate
dependent
III.   Dirty water/dust   Location/
Climate
dependent
IV.   Dew   Climate
dependent
V.   Freeze/thaw   Climate
dependent
VI.   Cold   Climate
dependent
VII.   Heat   Climate
dependent
VIII.   Ultra-Violet (UV) Radiation   Climate
dependent
IX.   Traffic Vibration   Location
dependent
X.   Biological Process   Climate
dependent
XI.   Ozone   Location
dependent
XII.   Water   Climate
dependent
XIII.   Water spray
Wet/dry   Location
dependent

This European Standard specifies requirements for assessing the working life and provides the relevant exposure conditions.
Standards of construction and any material tests conducted should provide evidence of resistance to specified conditions selected from the following:
I.   Chemical Agents   Location dependent
II.   De-icing salt   Location/climate dependent
III.   Dirty water/dust   Location/climate dependent
IV.   Dew   Climate dependent
V.   Freeze/thaw   Climate dependent
VI.   Cold   Climate dependent
VII.   Heat   Climate dependent
VIII.   UV Radiation   Climate dependent
IX.   Traffic Vibration   Location dependent
X.   Biological Process   Climate dependent
XI.   Ozone   Location dependent
XII.   Water   Climate dependent
XIII.   Water spray (Wet/dry)   Location dependent
NOTE   Combinations of different materials are worth a special attention, whether inside a single device or in combination with other devices (for example: a combination of different acoustic elements or another combination of acoustic and structural elements).

This European Standard specifies minimum requirements and other criteria for assessing the general safety and environmental performance of noise barriers and related devices acting on airborne sound propagation under typical rail-side conditions. Requirements for more onerous conditions are a matter for consideration by the designer. Appropriate test methods are provided where these are necessary, but for some aspects a declaration of material characteristics may be required for the information of designers. The treatment of each topic is covered separately in Annexes A to G.

This European Standard describes a test method for determining the intrinsic characteristics of sound diffraction of added devices installed on the top of railway noise barriers. The test method prescribes measurements of the sound pressure level at several reference points near the top edge of a noise barrier with and without the added device installed on its top. The intrinsic effectiveness of the added device is calculated as the difference between the measured values with and without the added devices, correcting for any change in height. In other words, the method described here gives the acoustic benefit of changing the shape and materials of the top edge over a simple barrier of the same height. This is an intrinsic characteristic of the added device, provided that the source and receiver positions are standardized. In practice, when the added device is placed over an existing barrier, it raises the height and this provides additional screening, depending on the source and receiver positions, not considered in this European Standard.
The test method is intended for the following applications:
-   preliminary qualification, outdoors or indoors, of added devices to be installed on noise barriers;
-   determination of sound diffraction index difference of added devices in actual use;
-   comparison of design specifications of an added device with actual performance data after the completion of the construction work;
-   verification of the long term performance of added devices (with a repeated application of the method);
-   interactive design process of new products, including the formulation of installation manuals.
The test method can be applied both in situ and on samples purposely built to be tested using the method described here.
Results are expressed as a function of frequency, in one-third octave bands between 100 Hz and 5 kHz. If it is not possible to get valid measurements results over the whole frequency range indicated, the results shall be given in the restricted frequency range and the reasons for the restriction(s) shall be clearly reported. A single-number rating is calculated from frequency data.
For indoor measurements, see Annex A.

This European standard defines the loading, the relevant load model positions and the internal forces acting on noise barriers, due to the air pressure wave set out in EN 1991 2:2003, 6.6.2. The vertical and horizontal shapes of the air pressure wave and the dynamic effects have been taken into account. The calculation method described in this European standard has been developed for noise barriers having a post-and-panel structure with piled foundations. It can also be used where cladding is attached to a rigid structure. For structures with piled foundations, an empirical formula for determination of the natural frequency is given in Annex A. Annex B contains an example of application of the calculation method for determination of internal forces and moments acting on a mid-post. The design of noise barriers (e.g. to fatigue resistance) is not part of this standard.

This Technical Specification specifies methods for the determination of insertion loss of outdoor noise barriers intended to shield railway noise. It specifies detailed procedures for in situ measurement of barrier insertion loss including microphone positions, source conditions and acoustic environments of the measurement sites.
This Technical Specification allows one to measure the insertion loss of a given noise barrier at a given site including given meteorological conditions. It does not make it possible to compare insertion loss values of an equivalent barrier at a different site. It can be used for comparing insertion loss values of different types of barriers at the same site under given meteorological conditions by the "direct method".
This Technical Specification gives a method for determining insertion loss:
a)   from the level difference before and after the installation of noise barriers (the "direct method") and when this is not possible because a barrier has already been installed;
b)   using an indirect method to estimate the sound pressure levels before installation of the barrier by measurement at another site which has been judged to be equivalent.
For equivalent sites, a close match is required in source characteristics, microphone locations, terrain profiles ground surface characteristics, surrounding artificial structures and meteorological conditions. This Technical Specification prescribes principles for ensuring that sufficiently equivalent conditions are maintained between "before" and "after" cases to permit certain, reliable and repeatable determination of barrier insertion loss.
This Technical Specification does not cover the determination of the intrinsic acoustic characteristics of the barrier, for example the sound insulation index and the sound absorption coefficient.
The equivalent continuous A-weighted sound pressure level and one-third-octave band sound pressure level are used as noise descriptors.
This Technical Specification can be used for routine determination of barrier performance or for engineering or diagnostic evaluation. It can be used in situations where the barrier is to be installed or has already been installed.

This document specifies a normalized railway noise spectrum for the evaluation and assessment of the acoustic performance of devices designed to reduce airborne railway noise near railways.
All noise reducing devices different from noise barriers and related devices acting on airborne sound propagation, e.g. devices for attenuation of ground borne vibration and on board devices are outside of the scope of this document.

This European Standard describes a test method for measuring a quantity representative of the intrinsic characteristics of airborne sound insulation for railway noise barriers: the sound insulation index.
The test method is intended for the following applications:
-   determination of the intrinsic characteristics of airborne sound insulation of noise barriers to be installed along railways, to be measured either on typical installations alongside railways or on a relevant sample section;
-   determination of the in situ intrinsic characteristics of airborne sound insulation of noise barriers in actual use;
-   comparison of design specifications with actual performance data after the completion of the construction work;
-   verification of the long term performance of noise barriers (with a repeated application of the method);
-   interactive design process of new products, including the formulation of installation manuals.
The test method is not intended for the following applications:
-   determination of the intrinsic characteristics of airborne sound insulation of noise barriers to be installed in reverberant conditions, e.g. inside tunnels or deep trenches or under covers.
Results are expressed as a function of frequency in one-third octave bands, where possible, between 100 Hz and 5 kHz. If it is not possible to get valid measurement results over the whole frequency range indicated, the results will be given in a restricted frequency range and the reasons for the restriction(s) will be clearly reported.
All noise reducing devices different from noise barriers and related devices acting on airborne sound propagation, e.g. devices for attenuation of ground borne vibration and on board devices are out of the scope of this European Standard.

This Technical Specification describes a test method for measuring a quantity representative of the intrinsic characteristics of sound reflection from railway noise barriers: the reflection index.
The test method is intended for the following applications:
- determination of the intrinsic characteristics of sound reflection of noise barriers to be installed along railways, to be measured either on typical installations alongside railways or on a relevant sample section;
- determination of the in situ intrinsic characteristics of sound reflection of noise barriers and claddings in actual use;
- comparison of design specifications with actual performance data after the completion of the construction work;
- verification of the long term performance of noise barriers and claddings (with a repeated application of the method).
The test method is not intended for the following applications:
- determination of the intrinsic characteristics of sound reflection of noise reducing devices to be installed in reverberant conditions, e.g. inside tunnels or deep trenches.
Results are expressed as a function of frequency, in one-third octave bands between 100 Hz and 5 kHz. If it is not possible to get valid measurements results over the whole frequency range indicated, the results should be given in a restricted frequency range and the reasons of the restriction(s) should be clearly reported.
All noise reducing devices different from noise barriers and related devices acting on airborne sound propagation, e.g. devices for attenuation of ground borne vibration and on board devices are out of the scope of this Technical Specification.

This European Standard specifies the laboratory method for measuring the sound absorption of flat noise barriers or flat claddings for retaining walls or tunnels. It covers the assessment of the intrinsic sound absorption performance of noise barriers and related devices acting on airborne sound propagation designed for railways which can reasonably be assembled inside the testing facility described in EN ISO 354. The test method in EN ISO 354, referred to in this European Standard, is strictly valid only for flat absorbers and in particular excludes devices which act as slightly damped resonators. Some devices will depart significantly from these requirements and in these cases care is needed in interpreting the results.
All noise reducing devices that differ from noise barriers and related devices acting on airborne sound propagation, e.g. devices for attenuation of ground borne vibration and on board devices are out of the scope of this European Standard.
NOTE   The test method in EN ISO 354 is based on measurements in a reverberation room where diffuse sound field conditions prevail. As a uniformly applicable method for the determination of the sound absorptive performance of noise reducing devices under free field conditions is still under development, the measurement results according to this European Standard are temporarily considered relevant for application on noise reducing devices in reverberant as well as in free field conditions.

This European Standard specifies the laboratory method for measuring the airborne sound insulation of noise barriers. It covers the assessment of the intrinsic airborne sound insulation performance of noise barriers and related devices acting on airborne sound propagation designed for railways which can reasonably be assembled inside the testing facility described in EN ISO 10140 series.
All noise reducing devices different from noise barriers and related devices acting on airborne sound propagation, e.g. devices for attenuation of ground borne vibration and on board devices are out of the scope of this European Standard.

This European Standard specifies a normalized railway noise spectrum for the evaluation and assessment of the acoustic performance of devices designed to reduce airborne railway noise near railways.
All noise reducing devices different from noise barriers and related devices acting on airborne sound propagation, e.g. devices for attenuation of ground borne vibration and on board devices, are out of the scope of this European Standard.

This European Standard specifies a normalised railway noise spectrum for the evaluation and assessment of the acoustic performance of devices designed to reduce airborne railway noise near railways.
All noise reducing devices that differ from noise barriers and related devices acting on airborne sound propagation, e.g. devices for attenuation of ground borne vibration and on board devices, are out of the scope of this European Standard.