Showing papers on "Noise barrier published in 2016"

State-of-the-Art Review on Sustainable Design and Construction of Quieter Pavements—Part 1: Traffic Noise Measurement and Abatement Techniques

Abstract: Noise pollution due to highway traffic has drawn the attention of transportation agencies worldwide. Noise pollution is an irritant to residents, especially in urban areas near roads with high traffic volume. In addition to its adverse effects on the quality of life, traffic noise can induce stress that could lead to sleep disturbance and anxiety. Traditionally, noise barrier walls have been used for highways to mitigate traffic noise. However, using barrier walls as a noise abatement measure has proven to be very expensive. In addition to the cost, noise barrier walls are not always effective because they must break the line of sight to work properly, which is not always possible in case of intersections or driveways. Therefore, researchers especially from Europe and USA have been very proactive to reduce the noise at source. A number of research studies show traffic noise can be reduced by using an alternative surface type or changing texture of the pavement while complying with other requirements of sustainability, i.e., safety, structural durability, construction and maintenance costs. This paper presents a comprehensive review of the research conducted on this subject. A review of the tire-pavement noise generation and amplification mechanism, various traffic noise measurement methods and correlation among these methods, in addition to the abatement techniques used by various agencies to reduce pavement noise, is also presented.

Options for reducing noise from roads and railway lines

Abstract: The fundamental noise generation mechanisms of road and rail vehicles are discussed with attention to noise abatement measures. Based on an evaluation of publicly available tire noise data and the European road traffic noise emission model CNOSSOS, it is shown that on the road side there is a significant noise reduction potential in the usage of low-noise tires. From a three months measurement campaign a noise model was derived to predict the maximal sound pressure level of heavy duty vehicles during a pass-by in 7.5 m distance with the parameters vehicle speed and number of axles. With help of recently published information about external costs caused by heavy duty vehicles and the noise prediction tool, a model was developed to derive a money equivalent that can be used as a bonus/malus in a heavy duty vehicle fee. As a measure at the infrastructure, the installation of low-noise pavements is an effective, durable and economically attractive measure. Recent experiences with different technologies from all over the world are compiled and evaluated. On the rail side, an overview of the possible noise reduction strategies is given, followed by a discussion of the current policy and legislation in the EU and on the national level of different European countries.

Active Acoustic Windows: Towards a Quieter Home

Abstract: Environmental noise (also known as noise pollution) is a prevalent feature of any urban soundscape. Of the numerous environmental noise sources (e.g., aircrafts, road traffic, railways, industries, and construction), the World Health Organization (WHO) has identified road traffic noise as one of the main contributors to urban noise pollution.

Open Noise Barriers Based on Sonic Crystals. Advances in Noise Control in Transport Infrastructures

Abstract: Noise control is an environmental problem of first magnitude nowadays. In this work, we present a new concept of acoustic screen designed to control the specific noise generated by transport infrastructures, based on new materials called sonic crystals. These materials are formed by arrangements of acoustic scatterers in air, and provide a new and different mechanism in the fight against noise from those of the classical screens. This mechanism is usually called multiple scattering and is due to their structuring in addition to their physical properties. Due to the separation between scatterers, these barriers are transparent to air and water allowing a reduction on their foundations. Tests carried out in a wind tunnel show a reduction of 42% in the overturning momentum compared to classical barriers. The acoustical performance of these barriers is shown in this work, explaining the new characteristics provided in the control of noise. Finally, an example of these barriers is presented and classified according to acoustic standardization tests. The acoustic barrier reported in this work provides a high technological solution in the field of noise control.

Evaluation of noise exposure before and after noise barriers, a simulation study in Istanbul

Abstract: Istanbul is the most prominent Turkish city in terms of the gradually worsening noise problems associated with the rapid increase in population. This study aims to investigate the noise exposure in the settlements around the link roads connecting the Bosporus Bridge to the European side of the city by the aid of simulations and noise mapping, in the frame of action planning studies performed in Istanbul. Noise maps were generated for Lden and Ln noise indicators with the help of a noise mapping software. Since a considerable part of the settlements is exposed to high noise levels, a noise barrier alongside the link road was proposed as a control measure by the aid of the acoustic simulation. Simulations with the noise barriers suggest that for the Lden time interval the noise affected area over 55 dBA would reduce by 10%, the number of dwellings by 26% and the number of inhabitants by 25%, whereas for the Ln time interval the noise affected area over 45 dBA would reduce by 5%, the number of dwelli...

A systolic FxLMS structure for implementation of feedforward active noise control on FPGA

Abstract: Active noise control (ANC) is an efficient technique to deal with low frequency noise that is difficult to be abated by noise barrier or sound absorbing material. Many successful ANC systems have adopted the feedforward filtered-x least mean squares (FxLMS) algorithm to reduce machinery noise. The noise canceling headset is another well known example, where the feedback control structure is favorable due to the small size. However, the feedback control structure is incapable of reducing broad band noise. Therefore, this paper investigates the feasibility of implementing the feedforward FxLMS algorithm in the noise canceling headset. Since the reference microphone has to be placed very close to the secondary source, we propose a systolic FxLMS structure that can be very efficiently implemented on the field programmable gate array (FPGA). Theoretical analysis and simulation results are presented to show the convergence behavior of the systolic FxLMS structure.

Selection of Quiet Pavement Technology for Polish Climate Conditions on the Example of CiDRO Project

Abstract: Transportation noise has a growing detrimental impact on the environment, humans health and living conditions. In addition to noise mitigation by erection of the expensive noise barriers, tire/pavement noise can be reduced “in source” by construction of special asphalt pavements. While that solution is commonly known in regions with moderate maritime climate (e.g. The Netherlands), in places with more harsh climate it is not popular. High number (>100/year) of freeze and thaw (F&T) cycles in Poland is a significant limitation for porous asphalt technology. This paper presents results of the research work conducted within research project called “Innovative pavement technology with reduced noise emission” with acronym CiDRO. The project was conducted by a consortium composed of Mostostal Warszawa (leader of the consortium), Warsaw University of Technology – Faculty of Civil Engineering and Road and Bridge Research Institute – Department of Pavement Technology (members of the consortium). This project was supported by Polish National Centre for Research and Development. Within the scope of the CiDRO project presented in this paper, various noise reducing asphalt technologies were tested in both laboratory and field sections. Those sections included the following types of wearing course: asphalt concrete AC 11 (reference), stone mastic (matrix) asphalt SMA 5 and SMA 8, open graded friction course OGFC 8 and OGFC 11, porous asphalt PA8 and PA11. The range of laboratory research program consists of typical quality control and evaluation studies of functional characteristics such as resistance to water and frost, low temperature cracking resistance, aging resistance, rheological properties and fatigue life. In addition, field tests such as noise emissions by CPX and SPB methods, texture depth, friction coefficient and in-situ water permeability were performed. Field tests were repeated following winter period. Moreover, to simulate clogging, dirt (previously collected road debris) was spread on the surface and cleaning treatment was performed using specialized equipment. Selected properties of the pavement surface were tested to determine the effectiveness of cleaning process. Finally, two most promising sections were proposed for construction as real traffic exposed roads and subjected for observation during their exploitation. An initial conclusions and recommendations were drawn regarding the mixture maximum aggregate size and air void content.

Low-noise Thin Surface Course – Evaluation of the Effectiveness of Noise Reduction☆

Abstract: As automobile traffic increases in urban areas, noise generated by vehicle traffic has become an increasing nuisance and a growing concern. Road traffic noise abatement has therefore become a major priority. New product is a low-noise mix designed to meet urban requirements. It is one of the products to meet the new expectations of those living in the vicinity of roads and of road users with respect to noise abatement and more broadly to environmental protection. Tested product is an innovation that combines exceptional acoustic and skid resistance properties. The proposed solution efficiently and sustainably combats rolling noise pollution generated by vehicle traffic. It has a lower risk of long-term silting up than porous asphalt. Based on its intrinsic properties, it is a surfacing of choice for construction and maintenance of urban and suburban pavements: streets, thoroughfares, highway access routes, roundabouts, etc. In addition to comfort and safety, it offers a uniform surface and a fine, aesthetically pleasing mosaic. In urban works, since it is applied in a thin layer it requires no manhole leveling and presents limited joint problems. For analysis of acoustic properties and their evolution over time, acoustic measurements were made in Poland and Czech Republic. Rolling noise measurements have been carried out on a variety of road sections laid with low-noise mix according to test method n 63 of the IFSTTAR (previously LCPC) and the standard XP S 31-145 “In-situ characterization of the sound performances of road surfacing. Continuous measurements of the noise generated by tire/roadway”. In our research program many aspects of noise reduction have been studied, both in laboratory (Research Center in Merignac, France) and on the job site, for example: influence of washing and weather condition on acoustic measurements, influence of speed measurements and additionally a different version of product has been tested.

Exploiting ground effects for surface transport noise abatement

Abstract: Growing 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 acoustically hard 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.

Environmental Noise Mitigation Measures for Lithuanian Railway Network

Abstract: Railways are one of the most environmentally friendly types of transport. Rail transport requires less energy and emits less hazardous substances, but biggest issues with railways are an environmental noise pollution noise. To reduce this noise different measures could be implemented in different places – at the source, between the source and the receiver, at the receiver. Unfortunately today in Lithuanian rail transport is not very popular mean of transport amongst travellers. Therefore, it is necessary to reconstruct railways lines to increase train speed, comfort for passengers, etc. In order to promote its development, minimal impact on environmental noise pollution must be ensured. Various parameters of track influence the level of emitted noise. This article presents an overview of noise mitigation measures in Lithuanian railway design documentation (rail type, wheel roughness, rail dampers, noise barriers, exchange of brake blocks, rail grinding, noise insulated windows, etc.) and also comparison of their effectiveness.

Development Of Green Curtain Noise Barrier Using Natural Waste Fibres

Abstract: Noise pollution is one of the major problems in industry. Noise, which is commonly known as undesired sound, comes from numerous industrial machineries and very harmful to the human body. One of the simplest ways to solve this problem is by employing a noise barrier or partition. Current noise barrier are mostly made from synthetic materials which apparently causes another serious problem to the human health. Investigation on the alternative acoustic materials particularly natural fibres has therefore been widely conducted by researchers to solve the problem. This paper introduces natural fibres i.e. paddy straw and coconut fibres as an additional acoustic material to form an eco-friendly noise barrier system. The natural fibre is mixed with synthetic fibre to form a dissipative layer inside the barrier to absorb sound energy. The sample is then tested inside an anechoic chamber to measure its sound pressure level, which is the most common considered value in industrial noise. From the experimental results, it is found that the natural fibres give considerable performance and very potential to substitute the synthetic fibres.

Suppression of diffracted sound by green walls

Abstract: Green walls covered with vegetation are used in urban areas to purify the air, improve the appearance of the landscape and reduce heat-island effects. They also improve the noise environment. It has been reported in previous studies that the surfaces of green walls have good sound-absorbing performance. However, the contribution of the greenery to the sound-insulation performance of green walls, which are also used as noise barriers, has not been verified quantitatively. In this study, the enhancement of the sound-absorption performance of a wall due to greening was verified via measurements using actual green walls and the results were compared with those of a steel noise barrier, which has limited sound-absorption performance. Numerical analyses using the boundary element method (BEM) were also conducted. As a result, it was confirmed that the sound-absorbing effect generated by wall greening reduces the diffracted noise, thus contributing to sound-insulation performance enhancement in areas above the noise barrier.

The relative importance of visual and sound design in the rehabilitation of a bridge connecting a highly populated area and a park

Abstract: Audio-visual interactions can have an important effect on people's perception of the urban environment. The aim of this study is to research to what extent such measures can help in improving citizens' noise perception, and in extension, in increasing the general quality of the urban environment. Different renovation designs in a degraded area were put to the test by means of a virtual reality experiment. The test is performed with 100 normal hearing participants experiencing a walk over a visually and acoustically degraded bridge that connects a highly populated area to a park over a highway. Interventions to improve that state were both visualized and auralized. The Virtual Reality Environment is experienced by the participants with Oculus 3D glasses and headphones. The auralization includes noise abatement measures such as the addition of (low-height) noise barriers. The corresponding noise reduction was calculated in detail with the FDTD method, resulting in frequency-dependent insertion losses filtering the B-field (ambisonics) recordings made along the bridge. The participants are invited on several days, and exposed to the same audio-samples but with different visuals each time. Detailed questionnaires will help unraveling the importance of the auditive and visual stimuli when assessing the environmental quality. In the current paper, the setup of the experiment is discussed.

Active Control of the Acoustic Quality in Open-plan Offices Using a Noise Barrier System with Sound Masking

Abstract: This thesis is concerned with the active control of the acoustic quality in open-plan offices, which is an important aspect affecting the job satisfaction of the employees. Two of the primary complaints about the working environment in open-plan offices are high background noise level and lack of speech privacy. Both of these acoustic problems can be dealt with by active methods: active noise control (ANC) for reducing background noise, and sound masking for improving speech privacy. In the context of the ANC in offices, this thesis presents an investigation of creating a quiet zone in the private workspace by using a compact active noise barrier (ANB) system. A novel hybrid (HB) control strategy, which controls the diffracting edge of the noise barrier using feedback (FB) control and reduces the noise at the head position of the listener behind the barrier using feedforward (FF) control simultaneously, is proposed. First, the issue of designing a robust adaptive FB controller with limited noise amplification for the HB control system is addressed. Then, a compact ANB system using the proposed HB control strategy is implemented. The noise reduction performance of the ANB has been investigated under different sound field conditions by simulations and experiments in an anechoic chamber. Finally, the effectiveness of the proposed ANB has been examined in a real office room. As for the sound masking, this thesis aims to find a selection criterion of the maskers used in offices. Using sound masking systems in the workspace has two objectives. One is to prevent the information leakage, and the other is to help the employees concentrate. The first objective requires high masking efficiency and effectiveness, and the latter one requires low annoyance of the maskers. Therefore, two listening experiments are designed and conducted to investigate the efficiency and annoyance of several maskers. According to the experimental results, a selection criterion has been considered. Based on the above investigations, a sound proof system that integrates the sound masking techniques into the ANB system is finally implemented, and the performance of the proposed system has been confirmed.

Application of Acoustic Materials in Civil Engineering

Abstract: Excessive noise energy over 60 dB is found to be disturbing and any noise over 75 dB can be considered as noisy Exposure to an extreme noise can be a health risk and can cause significant hearing problem Sound proofing is an important aspect for maintaining the health and well-being of the occupants of residential or commercial dwellers as well as to minimize disturbances to the neighbourhood The acoustic retrofitting or acoustic treatments are commonly used for domestic, residential or populated buildings in order to absorb unwanted noise echoing and to confine sound energy inside the room Noise walls and improved pavement materials are widely used to attenuate highway and freeway noise whilst aerated concrete and concrete walls are commonly used in buildings to prevent aeroplane noise from entering into residential buildings Acoustic baffle systems and panels are commonly used in public areas and commercial buildings Most of the Environmental Protection Authorities (EPA) around the world have regulations for residential noise, originated from vehicles, lawn mowers, electrical tools, domestic heating/coolers and radio or sound systems to ease neighbourhood noise This chapter reviews various sound proofing applications used in Civil and Building Engineering as well as common materials used by the industry

Environmentally Progressive Road Traffic Noise Reducing Devices and Materials

Abstract: This paper analyses issues of progressive road traffic noise reducing devices design and evaluating the quality of asphalt road surfaces from the perspective of the Permanent Sustainable Development, which is one of the horizontal priorities of the National Strategic Reference Framework for the period from 2007 to 2013. The horizontal priority (HP) Permanent Sustainable Development (PSD) of the National Strategic Reference Framework (NSRF) has been complementary affecting the objectives of the NSRF. The purpose of the HP is to ensure targeted achievement on several priorities of the NSRF, which cannot be provided by a single Operational Program (OP), but requires a coordinated approach combining several specific priorities / priority axes / actions, or more precisely the projects of particular OPs. Within the specific objective of enhancing the quality of the environment has been directly defined sub-goal - to reduce noise pollution of environment. The scientific paper is concerned with measurements of the noise production and sound propagation on four different roads, where the source of the noise was the same vehicle driving at five different speeds.

Self-Shading in Bifacial Photovoltaic Noise Barriers

Abstract: There is a large market potential for Bifacial Photovoltaic Noise Barriers (PVNB) due to their high energy output for any road orientation. A crucial parameter affecting their energy output is the so-called 'self-shading. In this research we evaluate the effect of self-shading on the energy production of both an east and west facing bifacial PVNB. We followed an approach consisting of 1) Experimental investigation by accurately monitoring the power output of two bifacial PVNB prototypes, 2) Shading simulation using in-house developed simulation methods. Results show that in particular noise barriers on north-south aligned roads suffer from self-shading because the support structure of the noise barrier itself casts a shadow on the PV modules around noon. A strong correlation is found between clearness index and energy yield loss. On sunny days the energy loss can be as high as 5%. The year average for the loss is about 3%. Clear design guidelines for minimizing the impact have been derived. We conclude that our measurement method, simulation tools and derived design guidelines provide a way to assess and minimize the effect of self-shading on the energy output of bifacial photovoltaic noise barriers, leading to better energy yields and more market success for this type of application.

Prevention of Noise Pollution caused by Highways in Settlement Areas via a Noise Insulation System

Abstract: The noise, which is taken as unimportant at first glance, had become one of the most important factors, causing pollution of environment, because of civilization. Together with the industrial development, mechanization in work places, increase in the number of highways, increased traffic load had made the noise an important problem in pollution and prevention of environment. In this project prevention of the noise caused by the intensive traffic and heavy vehicles in highways in settlement centers is aimed. When preparing the noise barrier system, it is considered that a double glass vacuumed insulation system placed on highway sides can prevent the noise, with the thought that the sound cannot propagate in space. A vehicle had been located and moved in the model road, and simultaneous noise measurements had been performed during the movement on both the road and outside of the double glass insulation system. After the results of noise measurements it is seen that the noise decreases by 14%-17% and reaches to acceptable normal conservation level 57-64 dB (decibel). Double glass insulation system had also prevented the panoroma pollution.

Optimization of some alternatives to noise barriers as noise mitigation measures on major roads in europe. case study of a highway in spain

Abstract: There is an extensive literature covering a number of considerations for installing noise barriers to protect living areas. In fact, noise barriers are the most popular mitigation measure on major roads across Europe. This paper aims to review some situations where the use of noise barriers is not fully recommended. Fortunately, there are available wide ranges of technical noise solutions as an alternative to the barriers. What we propose in this article is to create a simple procedure to help decision makers to decide if noise barrier is the best option for noise mitigation case by case. For this, we tested some alternatives through checking the acoustic performance of “ultra-quiet” pavement like PERS (Porous Elastic Road Surface), and a combination of speed reduction with other more common quiet pavement (in this case thin layer). The results have shown that the installation of PERS is one of the most promising solutions because, as all measures were taken on the noise source, reduces noise everywhere, but PERS does it in an impressive manner. Although its acoustic properties remain good over time, the negative part of PERS is its low durability that makes increase its installation costs by having to replace it too often. The paper, in addition to efficiency and cost, analyzes the criterion of visual impact that should be part of suitability analysis of any noise barrier construction.

Noise barrier on-line measurement method and system

Abstract: Embodiments of the invention provide a noise barrier on-line measurement method and a system. The noise barrier on-line measurement method comprises the following steps: step 1, a laser vision sensor acquires the relative displacement of a noise barrier when a train moves; step 2, whether the relative displacement is greater than a displacement threshold is judged, and a judgment result is generated; step 3, when the relative displacement is greater than the displacement threshold, the judgment result shows that there is a risk that the noise barrier may be loosened; and step 4, the judgment result is output. With the method and the system of the invention, the looseness fault of a high-speed railway noise barrier can be detected intelligently, and the problem that manual patrol inspection is of low efficiency and affected by subjective factors is overcome.