8 research outputs found
Attribute zur gesamtheitlichen Charakterisierung der Wahrnehmung von Straßenverkehrsgeräuschen
Die Lärmwirkungsforschung beschäftigt sich bereits seit vielen Jahren mit der Belastung durch Verkehrsgeräusche und den dadurch hervorgerufenen extra-auralen Lärmwirkungen einschließlich der Lärmbelästigung. Dabei wird die Belästigung üblicherweise in den Zusammenhang zum gemittelten Schalldruckpegel (z.B. LAeq, LDEN) der unerwünschten Geräuschquelle gestellt und Dosis-Wirkungsrelationen abgeleitet. Die Wirkung wird demnach nahezu ausschließlich mit dem Grad der Belästigung beschrieben und eine differenzierte Betrachtung der verschiedenen Aspekte der Geräuschwahrnehmung erfolgt nich
Noise emission from portals of road tunnels - scale model investigations
Schallreflexionen an den Innenwänden eines Straßentunnels erhöhen den im Tunnel herrschenden Geräuschpegel. Nach In-situ-Messungen in verschiedenen Straßentunneln kann die Erhöhung des Mittelungspegels in Tunnelmitte bis zu 14 dB(A) betragen. Durch schallabsorbierende Bekleidung der Tunnelinnenwände wird die Pegelerhöhung bis auf wenige Dezibel abgebaut. Die Reflexionen im Tunnelinnern führen weiter zu einer erhöhten Schallemission aus den Tunnelportalen, sodass der Immissionspegel in der Nähe der Portale ansteigt. Schallmessungen an einem im Maßstab 1:8 verkleinerten runden Tunnel und zwei im Maßstab 1:20 verkleinerten runden und rechteckigen Tunneln - alle mit senkrechten Portalen und schallreflektierenden Innenwänden - ergaben an Immissionsorten in 10 m Abstand zur Tunnelachse maximale Pegelerhöhungen von ungefähr 4 dB(A). Sie lagen in 20 m Abstand noch bei 2 dB(A). Durch relativ kurze Belegungslängen der Tunnelinnenwände mit schallabsorbierendem Material kann die maximale Pegelerhöhung auch im Nahbereich von Straße und Tunnelportal auf unkritische Werte unter 1 dB(A) abgesenkt werden. Anhand der Messergebnisse ließ sich ein einfaches Verfahren zur Berechnung der Erhöhung des Mittelungspegels an Immissionsorten vor den Portalen von Tunneln mit schallreflektierenden Innenwänden herleiten. Das Verfahren kann mit geringen Modifikationen auch zur Berechnung der Pegelerhöhung an Tunneln mit schallabsorbierender Bekleidung der Innenwände herangezogen werden
Lärmprobleme an den Portalen von Tunneln und Einhausungen
Im Nahbereich hochbelasteter Bundesfernstraßen sind Überschreitungen von Immissionsgrenzwerten um mehr als 15 dB(A) möglich, die durch normal hohe Lärmschutzwände nicht mehr abgebaut werden können. Zur Vermeidung ästhetisch nicht befriedigender und bautechnisch schwer beherrschbarer Lärmschutzwandhöhen kommt als aktive Schallschutzmaßnahme nur noch die Führung von Straßen in teuren Lärmschutztunneln oder Einhausungen in Frage. Das Bemühen, die Kosten eines solchen Lärmschutzes zu minimieren, kann aber zu einer Reihe von Lärmproblemen führen. Im Beitrag wird auf die Probleme "Schalldämmung", "Überstandslänge" und "erhöhte Emission durch das Tunnelportal" eingegangen
Calculation of weather-corrected traffic noise immission levels on the basis of emission data and meteorological quantities
The assessment methods for noise exposure from different modes of traffic are usually based on simplified models. Regarding meteorological influences, it is well known that weather conditions in favor of sound propagation can cause maximum noise levels which are not reflected in the averaged rating levels. Especially in larger distances from the emitter these effects become evident. Correction factors are not always sufficient to capture the strong impact of the actual atmospheric structure. An applicable and accurate meteorological model for obtaining the “real” immission load in residential areas can serve e.g. as a supplement to the averaged rating levels to better understand noise situation. In this study we look at the sound propagation models NMPB-Roads-2008 and Harmonoise, which include meteorological considerations. We compare them to the German RLS-90, discuss their advantages and drawbacks, and apply them to a simple weather-dependent test scenario to examine if their meteorologically corrected noise immission levels are feasible
Comprehensive noise assessment in complex situations with more than one mode of transport
The exposure to noise from more than one source is no rarity nowadays. In most cases the assessment of"br" immission load is performed for each traffic carrier individually and superposition of different sound levels is"br" not treated in any special way when mitigation measures are realized. Thus, health-impairing situations are not"br" properly resolved or even remain undetected. In order to establish a comprehensive approach for the joint"br" evaluation of road, railway, aircraft and shipping noise immission, we look at different test cases, which serve as"br" exemplary scenarios for critical noise situations. By comparing different calculation and assessment methods"br" (e.g. energetic sum, spectral analysis, weighted noise index, VDI 3722-2 ...) we want to give first answers to the"br" questions: How to calculate the overall sound level when several noise sources are present? How to consider the"br" diverse physiological and psychological effects of noise on people? What are possible unambiguous indicators"br" for triggering acoustically effective mitigation measures
SOPRANOISE: European Research on new techniques to characterize Noise Barriers acoustic performances
International audienceSOPRANOISE (Securing and Optimizing the Performance of Road trAffic noise barriers with New methOds and In-Situ Evaluation) is a new European research targeting the in-situ noise barrier acoustic performances (whatever along roads or railway tracks). Even if EN1793-5 and EN1793-6 have shown their ability to measure the sound absorption and the airborne sound insulation of noise barriers (NB) in-situ, there is still interest to simplify their use alongside roads and railway tracks. SOPRANOISE will update the State Of the Art about today methods, their significance and their accuracy to characterize the NB performances as well as their ability to be used in a quick and safe manner. Investigations will start from the easiest in-situ inspection methods up to improved versions of 1793-5 and -6. In-between, there is a gap for simplified and safe methods: SOPRANOISE aims to define the right method for the right step of decision, from the simplest to the most accurate. this research is funded by CEDR, with a schedule from 12/2019 up to 11/2021
Repeatability and reproducibility of in situ measurements of sound reflection and airborne sound insulation index of noise barriers
In Europe, in situ measurements of sound reflection and airborne sound insulation of noise barriers are usually done according to CEN/TS 1793-5. This method has been improved substantially during the EU funded QUIESST collaborative project. Within the same framework, an inter-laboratory test has been carried out to assess the repeatability and reproducibility of the newly developed method when applied to real-life samples, including the effect of outdoor weather variability and sample ageing. This article presents the statistical analysis of the inter-laboratory test results, and the values of the repeatability and the reproducibility, both in one-third octave bands and for the single-number ratings. The estimated reproducibility values can be used as the extended measure of uncertainty at the 95% credibility level in compliance with the ISO GUM. The repeatability and reproducibility values associated with airborne sound insulation are also compared with the corresponding values for laboratory measurements in building acoustics and an acceptable agreement is found
Repeatability and Reproducibility of In Situ Measurements of Sound Reflection and Airborne Sound Insulation Index of Noise Barriers
In Europe, in situ measurements of sound reflection and airborne sound insulation of noise barriers are usually done according to CEN/TS 1793-5. This method has been improved substantially during the EU funded QUIESST collaborative project. Within the same framework, an inter-laboratory test has been carried out to assess the repeatability and reproducibility of the newly developed method when applied to real-life samples, including the effect of outdoor weather variability and sample ageing. This article presents the statistical analysis of the inter-laboratory test results, and the values of the repeatability and the reproducibility, both in one-third octave bands and for the single-number ratings. The estimated reproducibility values can be used as the extended measure of uncertainty at the 95% credibility level in compliance with the ISO GUM. The repeatability and reproducibility values associated with airborne sound insulation are also compared with the corresponding values for laboratory measurements in building acoustics and an acceptable agreement is found