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Traffic Noise and Vibrations in Public Transportation Systems
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Traffic Noise and Vibrations in Public Transportation Systems

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Transportation and Future Mobility".

Deadline for manuscript submissions: 20 January 2025 | Viewed by 10029

Special Issue Editor

Dr. Tao Zhu

E-Mail Website
Guest Editor
State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, China
Interests: train dynamics; vehicle structure

Special Issue Information

Dear Colleagues,

Traffic-generated noise and vibration mainly appear during the operation of motor vehicles, urban rail transit vehicles, ships, and aircrafts. With people’s increasingly high requirement of living environment, determining how to solve this kind of problem from the source has gradually become a topic of great significance.

In this Special Issue of Applied Sciences on “Traffic Noise and Vibrations in Public Transportation Systems”, we will explore research and discussions on the latest technologies around the topic. If you are also interested in this topic, you are invited to submit your manuscripts.

Dr. Tao Zhu
Guest Editor

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Keywords

  • traffic noise
  • traffic vibration

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Published Papers (7 papers)

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Research

19 pages, 577 KiB  
Article
Impact of Ship Noise on Seafarers’ Sleep Disturbances and Daily Activities: An Analysis of Fatigue Increase and Maritime Accident Risk through a Survey
by Seok-Jin Kim, Tae-Youl Jeon and Young-Chan Lee
Appl. Sci. 2024, 14(9), 3757; https://doi.org/10.3390/app14093757 - 28 Apr 2024
Viewed by 1750
Abstract
This study delves into the impact of ship noise on seafarer well-being, emphasizing fatigue—a significant contributor to maritime accidents due to human error. The investigation, centered around the hypothesis that IMO ship construction standards may not adequately minimize noise levels in seafarer cabins, [...] Read more.
This study delves into the impact of ship noise on seafarer well-being, emphasizing fatigue—a significant contributor to maritime accidents due to human error. The investigation, centered around the hypothesis that IMO ship construction standards may not adequately minimize noise levels in seafarer cabins, seeks to establish whether these levels are sufficient to ensure seafarer security and prevent sleep disturbances. According to current IMO regulations, noise levels are set at 55 dB for vessels under 10,000 gross tonnage and 60 dB for those over 10,000, yet WHO guidelines recommend a maximum of 40 dB in bedrooms to avoid sleep disruption. A comprehensive survey involving 221 cadets demonstrates that 79.6% of participants experience sleep disturbances, work disruptions, and stress due to noise, indicating that the present noise standards are insufficient. This paper argues that reducing noise levels in individual cabins to below 40 dB is critical for enhancing seafarer health and safety and could significantly reduce human error-related maritime accidents. The findings advocate for more stringent noise control measures and regulatory reforms to bridge the knowledge gaps and improve labor protection in the maritime industry. Full article
(This article belongs to the Special Issue Traffic Noise and Vibrations in Public Transportation Systems)
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<p>Allowable Daily and Occasional Noise Exposure Zone in Ship.</p> Full article ">
18 pages, 23565 KiB  
Article
Bridge-Borne Noise Induced by High-Speed Freight Electric Multiple Units: Characteristics, Mechanisms and Control Measures
by Miao Du, Kaiyun Wang, Xin Ge and Xiaoan Zhang
Appl. Sci. 2024, 14(7), 2801; https://doi.org/10.3390/app14072801 - 27 Mar 2024
Cited by 1 | Viewed by 733
Abstract
The high-speed freight electric multiple unit (EMU) is one of the important development directions for railway freight transportation. To investigate the bridge radiation noise induced by the freight EMU, a noise prediction model consisting of the containers–vehicle–track–bridge dynamic model, finite element model, and [...] Read more.
The high-speed freight electric multiple unit (EMU) is one of the important development directions for railway freight transportation. To investigate the bridge radiation noise induced by the freight EMU, a noise prediction model consisting of the containers–vehicle–track–bridge dynamic model, finite element model, and boundary element model are established and validated. Through simulation, the bridge radiation noise under different train loading conditions is compared, and the noise radiation mechanism is revealed. Moreover, the noise reduction effect of the noise wall is studied, and the influences of noise wall heights and sound absorption materials are investigated. Results indicate that the bridge sound power and the sound pressure levels (SPLs) of near-field points increase slightly with train loads in the frequency range below 20 Hz and above 125 Hz, with a maximum increase of about 6.8 dB. The structure resonance, intense local vibration, and high acoustic radiation efficiency cause strong bridge radiation noise. The noise wall can realize a good overall noise reduction effect in the sound shadow zone; nevertheless, SPLs increased in areas between the bridge and the noise wall. The ground reflection affects the superposition of transmitted, reflected, and diffracted sound waves, which causes nonlinear relationships of noise reduction effects with the noise wall height. From the perspective of human hearing sensitivity, the loudness levels of typical field points increase with the frequency in the range of 20~80 Hz, and SPLs below 25 Hz are less than the threshold of hearing. Setting the noise wall can effectively reduce the loudness levels, and the reduction effect increases with the noise wall height. Full article
(This article belongs to the Special Issue Traffic Noise and Vibrations in Public Transportation Systems)
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Figure 1

Figure 1
<p>The prediction model of bridge-borne noise.</p> Full article ">Figure 2
<p>Model validation results: (<b>a</b>) arrangement of test points; (<b>b</b>) comparison of bridge acceleration in the time domain; (<b>c</b>) comparison of bridge acceleration RMS in the frequency domain; (<b>d</b>) comparison of 1/3 octave band SPLs.</p> Full article ">Figure 3
<p>Dynamic responses of the vehicle–track–bridge system under different load conditions: (<b>a</b>) vertical wheel–rail forces; (<b>b</b>) bridge deck accelerations.</p> Full article ">Figure 4
<p>Comparison of bridge acoustic powers under different load conditions.</p> Full article ">Figure 5
<p>Comparisons of 1/3 octave band SPLs under different loading conditions at field points (<b>a</b>) N1; (<b>b</b>) N2; (<b>c</b>) N3; (<b>d</b>) N4; (<b>e</b>) N5; and (<b>f</b>) N6.</p> Full article ">Figure 6
<p>The panels’ sound pressure contributions under the loaded containers condition at field points (<b>a</b>) N1; (<b>b</b>) N2; (<b>c</b>) N3; (<b>d</b>) N4; (<b>e</b>) N5; and (<b>f</b>) N6.</p> Full article ">Figure 7
<p>Characteristics of the bridge vibrations near peak frequencies of the acoustic power.</p> Full article ">Figure 8
<p>The bridge acoustic radiation efficiency.</p> Full article ">Figure 9
<p>Layout of typical field points.</p> Full article ">Figure 10
<p>Comparisons of frequency-domain SPLs with/ without noise wall at filed points (<b>a</b>) N1′; (<b>b</b>) N2′; (<b>c</b>) N3′; (<b>d</b>) N4′; (<b>e</b>) N5′; (<b>f</b>) N6′; (<b>g</b>) N7′; (<b>h</b>) N8′; (<b>i</b>) N9′; (<b>j</b>) N10′; (<b>k</b>) N11′; and (<b>l</b>) N12′.</p> Full article ">Figure 10 Cont.
<p>Comparisons of frequency-domain SPLs with/ without noise wall at filed points (<b>a</b>) N1′; (<b>b</b>) N2′; (<b>c</b>) N3′; (<b>d</b>) N4′; (<b>e</b>) N5′; (<b>f</b>) N6′; (<b>g</b>) N7′; (<b>h</b>) N8′; (<b>i</b>) N9′; (<b>j</b>) N10′; (<b>k</b>) N11′; and (<b>l</b>) N12′.</p> Full article ">Figure 11
<p>Comparisons of 1/3 octave band SPLs and insertion losses under different noise wall height conditions at field points (<b>a</b>) N1′; (<b>b</b>) N2′; (<b>c</b>) N3′; (<b>d</b>) N4′; (<b>e</b>) N5′; and (<b>f</b>) N9′.</p> Full article ">Figure 11 Cont.
<p>Comparisons of 1/3 octave band SPLs and insertion losses under different noise wall height conditions at field points (<b>a</b>) N1′; (<b>b</b>) N2′; (<b>c</b>) N3′; (<b>d</b>) N4′; (<b>e</b>) N5′; and (<b>f</b>) N9′.</p> Full article ">Figure 12
<p>Insertion losses distributions under the noise wall heights of (<b>a</b>) 4 m, (<b>b</b>) 6 m, and (<b>c</b>) 8 m at 9 Hz; (<b>d</b>) 4 m, (<b>e</b>) 6 m, and (<b>f</b>) 8 m at 71 Hz; (<b>g</b>) 4 m, (<b>h</b>) 6 m, and (<b>i</b>) 8 m at 82 Hz.</p> Full article ">
15 pages, 40452 KiB  
Article
Experimental Light Rail Traffic Noise Assessment in a Metropolitan Area
by João Lázaro, Pedro Alves Costa and Luís Godinho
Appl. Sci. 2024, 14(3), 969; https://doi.org/10.3390/app14030969 - 23 Jan 2024
Cited by 1 | Viewed by 1291
Abstract
The growth in the utilization and development of rail transport within urban networks is crucial for transitioning towards a more sustainable form of mobility. However, challenges related to discomfort and noise pollution arising from rail traffic must be addressed and mitigated to foster [...] Read more.
The growth in the utilization and development of rail transport within urban networks is crucial for transitioning towards a more sustainable form of mobility. However, challenges related to discomfort and noise pollution arising from rail traffic must be addressed and mitigated to foster a harmonious coexistence between residents and trains. This study focuses on analyzing an experimental campaign conducted on the surface metropolitan network of Porto to study and identify the frequency content and pressure levels associated with light rail traffic. The presented experimental campaign holds significant relevance as it comprises various and distinct circulation conditions within the railway network, enabling a comprehensive characterization of railway noise. The collected data indicates a noticeable increase in sound pressure levels as the speed of circulation rises, particularly emphasizing the 1/3 octave band centered around 1000 Hz. The choice of tracks with components having a limited capacity for absorbing acoustic energy leads to a significant rise in noise levels compared to track solutions with elements exhibiting excellent acoustic energy absorption. Furthermore, the study highlights a substantial increase in noise levels (10 dBA) associated with small radius curves, even at low speeds. These findings underscore the importance of considering the track characteristics and geometric features in noise assessment within rail networks. Therefore, the insights gained from this experimental campaign contribute significantly to the understanding and comprehensive characterization of railway noise under diverse circulation conditions within the railway network. Full article
(This article belongs to the Special Issue Traffic Noise and Vibrations in Public Transportation Systems)
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Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Evolution of the contribution of the different sources as a function of the circulation velocity (adapted from [<a href="#B20-applsci-14-00969" class="html-bibr">20</a>]).</p> Full article ">Figure 2
<p>Photographs of the type of tracks: (<b>a</b>) Type I; (<b>b</b>) Type II; (<b>c</b>) Type III; (<b>d</b>) Type IV; (<b>e</b>) Bridge.</p> Full article ">Figure 3
<p>Representation of vehicles operating in the metropolitan area of Porto: (<b>a</b>) Photograph of the vehicle <span class="html-italic">Eurotram</span>; (<b>b</b>) Photograph of the vehicle <span class="html-italic">Flexity Swift</span>; (<b>c</b>) Schematic representation of the vehicle load distribution <span class="html-italic">Eurotram</span>; (<b>d</b>) Schematic representation of the vehicle load distribution <span class="html-italic">Flexity Swift</span>.</p> Full article ">Figure 4
<p>Experimental setup for the acoustic signal acquisition; (1) Behringer ECM 8000 microphone, (2) computer, (3) Focusrite Sclarett 4Pre USB acquisition unit.</p> Full article ">Figure 5
<p>Schematic diagram showing the position of the microphones in relation to the track.</p> Full article ">Figure 6
<p>Comparison of sound pressure levels (dBA) for <span class="html-italic">Flexity Swift</span> and <span class="html-italic">Eurotram</span> vehicles traveling at 58 km/h on a Type II track: (<b>a</b>) Microphone 1; (<b>b</b>) Microphone 2.</p> Full article ">Figure 7
<p><span class="html-italic">Flexity Swift</span> and <span class="html-italic">Eurotram</span> vehicles traveling at 30 km/h on a Type II track: (<b>a</b>) Microphone 1; (<b>b</b>) Microphone 2.</p> Full article ">Figure 8
<p><span class="html-italic">Flexity Swift</span> and <span class="html-italic">Eurotram</span> vehicles traveling at 40 km/h on a Type III track: (<b>a</b>) Microphone 1; (<b>b</b>) Microphone 2.</p> Full article ">Figure 9
<p>Comparison between different speeds for the <span class="html-italic">Flexity Swift</span> vehicle operating on a Type II track: (<b>a</b>) Microphone 1; (<b>b</b>) Microphone 2.</p> Full article ">Figure 10
<p>Comparison between different speeds for the <span class="html-italic">Eurotram</span> vehicle operating on a Type II track: (<b>a</b>) Microphone 1; (<b>b</b>) Microphone 2.</p> Full article ">Figure 11
<p>Comparison between different speeds for the <span class="html-italic">Eurotram</span> vehicle operating on a Type I track: (<b>a</b>) Microphone 1; (<b>b</b>) Microphone 2.</p> Full article ">Figure 12
<p>Comparison of sound pressure levels for three different types of the track (I, II, III) for a <span class="html-italic">Eurotram</span> vehicle operating at 40 km/h: (<b>a</b>) Microphone 1; (<b>b</b>) Microphone 2.</p> Full article ">Figure 13
<p>Site illustration with curved track geometry and the corresponding signalling (+) of the measurement location.</p> Full article ">Figure 14
<p>Comparison of sound pressure levels of a straight measuring section and a measurement on a curved section for a <span class="html-italic">Eurotram</span> vehicle on a Type IV track: (<b>a</b>) Microphone 1; (<b>b</b>) Microphone 2.</p> Full article ">Figure 15
<p>Spectrograms of the vehicles passing on the curved measuring section and on the straight section: (<b>a</b>) Microphone 3—curved track; (<b>b</b>) Microphone 3—straight track; (<b>c</b>) Microphone 4—curved track; (<b>d</b>) Microphone 4—straight track.</p> Full article ">Figure 16
<p>Comparison of sound pressure levels for the <span class="html-italic">Flexity Swift</span> vehicle traveling on a Type II track, under acceleration and at null acceleration, for a speed of 77 km/h: (<b>a</b>) Microphone 1; (<b>b</b>) Microphone 2.</p> Full article ">Figure 17
<p>Comparison of sound pressure levels for the <span class="html-italic">Eurotram</span> vehicle traveling on a Type II track, under acceleration and at null acceleration, for a speed of 58 km/h: (<b>a</b>) Microphone 1; (<b>b</b>) Microphone 2.</p> Full article ">Figure 18
<p>Spectrograms of a <span class="html-italic">Flexity Swift</span> vehicle passing the measuring section at acceleration and null acceleration: (<b>a</b>) Microphone 4—accelerating; (<b>b</b>) Microphone 4—null acceleration.</p> Full article ">Figure 19
<p>Spectrograms of a <span class="html-italic">Eurotram</span> vehicle passing the measuring section at acceleration and at null acceleration: (<b>a</b>) Microphone 4—accelerating; (<b>b</b>) Microphone 4—null acceleration.</p> Full article ">Figure 20
<p>Comparison between the sound pressure levels of the <span class="html-italic">Eurotram</span> vehicle traveling at approximately 20 km/h on Type I, III and IV tracks and on a metal frame bridge.</p> Full article ">
15 pages, 5652 KiB  
Article
Research on the Arrangement of Additional Source for Large Space Protection of an Active Noise Barrier
by Yanpeng Wang, Zhibo Chang, Guoqiang Chen and Jiahao Liu
Appl. Sci. 2024, 14(2), 885; https://doi.org/10.3390/app14020885 - 19 Jan 2024
Viewed by 1077
Abstract
When active noise control technology is applied to traffic noise control, additional sources are often added to the facade of the barrier, and error sensors are placed in the protected area. The noise reduction effect in the area without error sensors is often [...] Read more.
When active noise control technology is applied to traffic noise control, additional sources are often added to the facade of the barrier, and error sensors are placed in the protected area. The noise reduction effect in the area without error sensors is often ignored. In this paper, the effect of the additional source configuration on the sound field in the space without error sensors is researched. By analyzing the directivity and distribution of the sound field at the top of the barrier under various conditions, it is believed that the optimal location of the additional source is related to the height of the primary source and the barrier. An approximate model is established to evaluate the optimal location of the additional source for achieving a good noise reduction effect in a large space. Experiments are also carried out to verify the model. The conclusions are beneficial for improving the noise reduction effect in the area higher than the barrier and without error microphones. Full article
(This article belongs to the Special Issue Traffic Noise and Vibrations in Public Transportation Systems)
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Figure 1

Figure 1
<p>The scheme of an active noise barrier.</p> Full article ">Figure 2
<p>Calculation results of sound field when the additional source is located at different locations (800 Hz).</p> Full article ">Figure 3
<p>Directivity of the sound field over the barrier when the primary source is located at 0.5 m above the ground.</p> Full article ">Figure 4
<p>Directivity of the sound field over the barrier when the primary source is located at 1 m above the ground.</p> Full article ">Figure 5
<p>Directivity of the sound field over the barrier when the primary source is located at 5.75 m from the barrier.</p> Full article ">Figure 5 Cont.
<p>Directivity of the sound field over the barrier when the primary source is located at 5.75 m from the barrier.</p> Full article ">Figure 6
<p>Directivity of the sound field over the barrier when the primary sources are located in two lanes.</p> Full article ">Figure 7
<p>The overall SPLs at <span class="html-italic">R</span>. (<b>a</b>) The primary source is located at 0.5 m above the ground. (<b>b</b>) The primary source is located at 1 m above the ground.</p> Full article ">Figure 8
<p>The overall SPLs at <span class="html-italic">R</span> when the height of the barrier is 1.5 m. (<b>a</b>) The primary source is located at 0.5 m above the ground. (<b>b</b>) The primary source is located at 1 m above the ground.</p> Full article ">Figure 9
<p>The scheme of the experiments.</p> Full article ">Figure 10
<p>The SPLs measured at the frequency of 125 Hz, 250 Hz, 500 Hz, and 1000 Hz.</p> Full article ">
18 pages, 9095 KiB  
Article
Alleviation Effects of Hoods at the Entrances and Exits of High-Speed Railway Tunnels on the Micro-Pressure Wave
by Weibin Ma, Yufei Fang, Tao Li and Mingyu Shao
Appl. Sci. 2024, 14(2), 692; https://doi.org/10.3390/app14020692 - 13 Jan 2024
Cited by 3 | Viewed by 1152
Abstract
The MPW that emits from a tunnel’s exit when a high-speed train passes through is a serious environmental problem which increases rapidly with the speed of the train. To alleviate the MPW problem at 400 km/h, the aerodynamic effects caused by the hood [...] Read more.
The MPW that emits from a tunnel’s exit when a high-speed train passes through is a serious environmental problem which increases rapidly with the speed of the train. To alleviate the MPW problem at 400 km/h, the aerodynamic effects caused by the hood located at the entrance or exit of a tunnel are studied by numerical method, and the influences of hood geometry, such as an enlarged cross-section, oblique entrance, and opening holes on the MPW, are also investigated. The research indicates that the enlarged cross-section of the hood at the entrance and exit of the tunnel has opposite effects on the MPW, and the oblique section can alleviate the MPW by extending the rising time of the compression wave and increasing the spatial angle at the hood exit. The pressure gradient can be mitigated through delaying the rising of the compression wave by opening holes on the side wall of the hood, and the relief effects of the holes can reduce the MPW further. The MPW problem when a train passes through a tunnel at 400 km/h can be effectively alleviated by an optimized oblique enlarged hood with opening holes, even up to train speeds of 500 km/h. Full article
(This article belongs to the Special Issue Traffic Noise and Vibrations in Public Transportation Systems)
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Figure 1

Figure 1
<p>Schematic diagram of the geometric model: (<b>a</b>) Three views of the train nose; (<b>b</b>) Tunnel section; (<b>c</b>) Sketch of the hood.</p> Full article ">Figure 2
<p>Computational domain and boundary conditions.</p> Full article ">Figure 3
<p>Monitoring points in the simulation: (<b>a</b>) Hood at tunnel entrance; (<b>b</b>) hood at tunnel exit.</p> Full article ">Figure 4
<p>Grid distribution of the model: (<b>a</b>) Mesh of tunnel and train; (<b>b</b>) Mesh of hood.</p> Full article ">Figure 5
<p>Comparison of pressure obtained by numerical simulation and field measurement: (<b>a</b>) Pressure at 140 m; (<b>b</b>) Pressure at 400 m.</p> Full article ">Figure 6
<p>Comparison of tunnel aerodynamics with different types of hoods: (<b>a</b>) Tunnel with different hoods; (<b>b</b>) Pressures at RP point; (<b>c</b>) Pressure gradient at RP point; (<b>d</b>) MPW at RM point.</p> Full article ">Figure 7
<p>The effects of hood length on tunnel aerodynamics: (<b>a</b>) Pressure gradient at RP point; (<b>b</b>) MPW at RM point.</p> Full article ">Figure 8
<p>The effects of cross-section area of entrance hood on tunnel aerodynamics: (<b>a</b>) Pressure gradient at RP point; (<b>b</b>) MPW at RM point.</p> Full article ">Figure 9
<p>The peak values of pressure gradient and MPW of the three stages with different hood areas: (<b>a</b>) Pressure gradient at RP point; (<b>b</b>) MPW at RM point.</p> Full article ">Figure 10
<p>The effects of oblique hood entrance on tunnel aerodynamics: (<b>a</b>) Pressure gradient at RP point; (<b>b</b>) MPW at RM point.</p> Full article ">Figure 11
<p>The effects of number of holes at entrance hood on tunnel aerodynamics: (<b>a</b>) Pressure gradient at RP point; (<b>b</b>) MPW at RM point.</p> Full article ">Figure 12
<p>The effects of position of holes on tunnel aerodynamics: (<b>a</b>) Pressure gradient at RP point; (<b>b</b>) MPW at RM point.</p> Full article ">Figure 13
<p>The effects of cross-section area of exit hood on the maximum values of pressure gradient and MPW.</p> Full article ">Figure 14
<p>Pressure contours with different hood exits.</p> Full article ">Figure 15
<p>The effects of oblique hood exit on the MPW.</p> Full article ">Figure 16
<p>The effects of number of holes at the exit hood on tunnel aerodynamics: (<b>a</b>) Pressure gradient at RH point; (<b>b</b>) MPW at RM point.</p> Full article ">Figure 17
<p>The effects of number of holes on tunnel aerodynamics: (<b>a</b>) Pressure gradient at RH point; (<b>b</b>) MPW at RM point.</p> Full article ">
18 pages, 3301 KiB  
Article
Development and Testing of an Active Noise Control System for Urban Road Traffic Noise
by Biyu Yang, Jiacun Yin, Zhoujing Ye, Songli Yang and Linbing Wang
Appl. Sci. 2024, 14(1), 175; https://doi.org/10.3390/app14010175 - 25 Dec 2023
Cited by 1 | Viewed by 2138
Abstract
As urbanization accelerates, the increasing number of vehicles and travel demands contribute to escalating road traffic noise pollution. Although passive noise control techniques such as noise barriers and green belts effectively mitigate noise, they occupy urban space, exacerbating the scarcity and high cost [...] Read more.
As urbanization accelerates, the increasing number of vehicles and travel demands contribute to escalating road traffic noise pollution. Although passive noise control techniques such as noise barriers and green belts effectively mitigate noise, they occupy urban space, exacerbating the scarcity and high cost of already congested city areas. Emerging as a novel noise reduction strategy, active noise control (ANC) eliminates the need for physical isolation structures and addresses the noise within specific frequency ranges more effectively. This paper investigates the characteristics of urban road traffic noise and develops an ANC prototype. Utilizing the Least Mean Squares (LMS) algorithm, we conduct active noise control tests for various types of single- and dual-frequency noise within the prototype’s universal platform to validate its actual noise reduction capabilities. The study demonstrates that urban road traffic noise is mostly in the mid- to low-frequency range (below 2000 Hz). The developed ANC prototype significantly reduces single- or dual-frequency noise within this range, achieving a maximum noise reduction of nearly 30 dB(A). Future research should expand noise reduction tests across more frequency bands and assess the noise reduction effectiveness against real road traffic noise. Full article
(This article belongs to the Special Issue Traffic Noise and Vibrations in Public Transportation Systems)
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Figure 1

Figure 1
<p>Road traffic noise testing setup and locations, temperature, wind, distance, and height from road.</p> Full article ">Figure 2
<p>Noise levels and spectrum chart at test points.</p> Full article ">Figure 3
<p>The spectrum of traffic noise at different vehicle speeds for three vehicle categories: small vehicles, medium vehicles, and large vehicles.</p> Full article ">Figure 4
<p>Schematic diagram of the broadband feedforward system [<a href="#B48-applsci-14-00175" class="html-bibr">48</a>].</p> Full article ">Figure 5
<p>Adaptive filter based on Least Mean Squares (LMS) algorithm [<a href="#B52-applsci-14-00175" class="html-bibr">52</a>,<a href="#B53-applsci-14-00175" class="html-bibr">53</a>].</p> Full article ">Figure 6
<p>Hardware platform design of active noise control prototype system.</p> Full article ">Figure 7
<p>Noise signal data transmission and processing.</p> Full article ">Figure 8
<p>Schematic diagram of the developed active noise control system test.</p> Full article ">Figure 9
<p>Maximum noise reduction and relative positions under different frequency noise.</p> Full article ">Figure 10
<p>Single-frequency test results.</p> Full article ">Figure 11
<p>Maximum noise reduction and relative positions under different dual-frequency noise.</p> Full article ">Figure 12
<p>Dual-frequency test results. (<b>a</b>) Comparison for 100 Hz + 1000 Hz. (<b>b</b>) Comparison for 200 Hz + 1000 Hz.</p> Full article ">
17 pages, 3699 KiB  
Article
Experimental Investigation and In-Situ Testing of Traffic-Induced Vibrations on the Adjacent Ruins of an Ancient Cultural Sites
by Liming Zhu, Jiang Meng, Lingkun Chen and Xiaolun Hu
Appl. Sci. 2023, 13(24), 13347; https://doi.org/10.3390/app132413347 - 18 Dec 2023
Viewed by 1180
Abstract
Background: Studying the effects of traffic vibration on adjacent structures has produced fruitful results, but there is a lack of systematic research on the protection, assessment, and ambient vibration effects on cultural relics, and the majority of the studies focus on above-ground buildings, [...] Read more.
Background: Studying the effects of traffic vibration on adjacent structures has produced fruitful results, but there is a lack of systematic research on the protection, assessment, and ambient vibration effects on cultural relics, and the majority of the studies focus on above-ground buildings, with less research conducted on underground cultural relic sites. Objective: In order to investigate the effects of road-traffic-induced vibration on nearby underground sites, the distance between them was precisely determined. Methodology/approach: The site of Chengshang Village in Jurong City, Nanjing, China, was chosen as the research object, and the vibration of the underground site caused by traffic volume was measured on-site. Based on statistical analysis of experimental data, the vibration velocity was deduced as a function of the vehicle’s speed and the vibration source’s distance. Results: The excellent frequency band for traffic load vibration is between 0 and 40 Hz, and the attenuation speed of high-frequency vibration is faster than that of low-frequency vibration; the vibration speed is positively correlated with the speed of the vehicle, and the distance from the vibration source is exponentially attenuated; and under the condition of the determined limit value of the load and the vibration speed, the safety distance increases. Conclusions: This research utilizes the collected data to describe the relationship between the vibration velocity and the distance from the vibration source. Additionally, it estimates the appropriate distance at which cultural relics should be placed from the road to ensure their safety. The study’s findings may serve as a valuable point of reference for traffic planning and the preservation of underground cultural monuments. Full article
(This article belongs to the Special Issue Traffic Noise and Vibrations in Public Transportation Systems)
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Figure 1
<p>Plane figure of Chengshang Village ruins. (<b>a</b>) An aerial photograph captured by a drone; (<b>b</b>) A red line delineating the location of Chengshang Village; and (<b>c</b>) Chinese signage bearing the inscription “Chengshang Village Site Protection Notice”.</p> Full article ">Figure 2
<p>Schematic diagram of stratigraphic accumulation of the Chengshang Village ruins.</p> Full article ">Figure 3
<p>Layout diagram of vibration measuring points.</p> Full article ">Figure 4
<p>The vibration response of different travel speeds.</p> Full article ">Figure 5
<p>Time-history curves of vibration response at different points. (<b>a</b>) Travel speed 10 km/h; (<b>b</b>) Travel speed 20 km/h; (<b>c</b>) Travel speed 40 km/h; (<b>d</b>) Travel speed 60 km/h.</p> Full article ">Figure 5 Cont.
<p>Time-history curves of vibration response at different points. (<b>a</b>) Travel speed 10 km/h; (<b>b</b>) Travel speed 20 km/h; (<b>c</b>) Travel speed 40 km/h; (<b>d</b>) Travel speed 60 km/h.</p> Full article ">Figure 6
<p>Vibration velocity spectrum response at different travel speeds. (<b>a</b>) Travel speed 10 km/h; (<b>b</b>) Travel speed 20 km/h; (<b>c</b>) Travel speed 40 km/h; (<b>d</b>) Travel speed 60 km/h.</p> Full article ">Figure 6 Cont.
<p>Vibration velocity spectrum response at different travel speeds. (<b>a</b>) Travel speed 10 km/h; (<b>b</b>) Travel speed 20 km/h; (<b>c</b>) Travel speed 40 km/h; (<b>d</b>) Travel speed 60 km/h.</p> Full article ">Figure 7
<p>Decay relationships between vibration velocity and distance. (<b>a</b>) Travel speed 10 km/h; (<b>b</b>) Travel speed 20 km/h; (<b>c</b>) Travel speed 40 km/h; (<b>d</b>) Travel speed 60 km/h.</p> Full article ">Figure 8
<p>Safe area determined by driving speed and safe distance.</p> Full article ">Figure 9
<p>Similar studies.</p> Full article ">
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