Experimental Study on the Forced Ventilation Safety during the Construction of a Large-Slope V-Shaped Tunnel
The special large-slope V-shaped structure of underwater tunnels changes the ventilation characteristics during tunnel construction, making the traditional experience limited. Therefore, it is urgent to study the influence of the special structure on the safety of the air environment during construc...
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MDPI AG
2024-03-01
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author | Linghong Yi Xiaoni Wang Yongjiang Shen |
author_facet | Linghong Yi Xiaoni Wang Yongjiang Shen |
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description | The special large-slope V-shaped structure of underwater tunnels changes the ventilation characteristics during tunnel construction, making the traditional experience limited. Therefore, it is urgent to study the influence of the special structure on the safety of the air environment during construction. In this paper, a series of small-scale experiments were conducted to investigate the ventilation characteristics of V-shaped tunnels. The coupled effects of ventilation parameters (distance of duct outlet from working face <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>L</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula>, air velocity at the duct outlet <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>u</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula>) and structural characteristics (digging length <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>L</mi><mi>d</mi></msub></mrow></semantics></math></inline-formula>, slope of the uphill section <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>θ</mi></semantics></math></inline-formula>) were considered. The extreme slope of the V-shaped tunnel of 8% was considered. The flow field and pollutant transport law were determined by using CO as a tracer in the experiments. The results show that <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>u</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula> has a positive impact on the air return velocity, while <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>L</mi><mi>d</mi></msub></mrow></semantics></math></inline-formula> has a negative impact, and neither of the other two factors has a significant effect. The transport characteristics of CO in V-shaped tunnels differ from those in flat tunnels, with the former tending to cause unconventional areas of high pollutant concentrations in the horizontal sections. Furthermore, the correlations between CO concentration and distance, ventilation time, and the influence factors discussed in this paper are derived from the experimental results. The conclusions provide guidance for the construction of V-shaped tunnels to prevent air pollution in the construction environment and to improve the working conditions of laborers. Additionally, it can also enrich the ventilation experience in tunnel construction. |
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spelling | doaj.art-edfc66dee6e4416bb9f5ece3a0f412402024-04-12T13:15:12ZengMDPI AGApplied Sciences2076-34172024-03-01147292410.3390/app14072924Experimental Study on the Forced Ventilation Safety during the Construction of a Large-Slope V-Shaped TunnelLinghong Yi0Xiaoni Wang1Yongjiang Shen2Institute of Disaster Prevention Science and Safety Technology, School of Civil Engineering, Central South University, Changsha 410075, ChinaInstitute of Disaster Prevention Science and Safety Technology, School of Civil Engineering, Central South University, Changsha 410075, ChinaInstitute of Disaster Prevention Science and Safety Technology, School of Civil Engineering, Central South University, Changsha 410075, ChinaThe special large-slope V-shaped structure of underwater tunnels changes the ventilation characteristics during tunnel construction, making the traditional experience limited. Therefore, it is urgent to study the influence of the special structure on the safety of the air environment during construction. In this paper, a series of small-scale experiments were conducted to investigate the ventilation characteristics of V-shaped tunnels. The coupled effects of ventilation parameters (distance of duct outlet from working face <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>L</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula>, air velocity at the duct outlet <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>u</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula>) and structural characteristics (digging length <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>L</mi><mi>d</mi></msub></mrow></semantics></math></inline-formula>, slope of the uphill section <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>θ</mi></semantics></math></inline-formula>) were considered. The extreme slope of the V-shaped tunnel of 8% was considered. The flow field and pollutant transport law were determined by using CO as a tracer in the experiments. The results show that <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>u</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula> has a positive impact on the air return velocity, while <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>L</mi><mi>d</mi></msub></mrow></semantics></math></inline-formula> has a negative impact, and neither of the other two factors has a significant effect. The transport characteristics of CO in V-shaped tunnels differ from those in flat tunnels, with the former tending to cause unconventional areas of high pollutant concentrations in the horizontal sections. Furthermore, the correlations between CO concentration and distance, ventilation time, and the influence factors discussed in this paper are derived from the experimental results. The conclusions provide guidance for the construction of V-shaped tunnels to prevent air pollution in the construction environment and to improve the working conditions of laborers. Additionally, it can also enrich the ventilation experience in tunnel construction.https://www.mdpi.com/2076-3417/14/7/2924V-shaped tunnel under constructionexperimental studyforced ventilationconstruction environmenttunnel structure |
spellingShingle | Linghong Yi Xiaoni Wang Yongjiang Shen Experimental Study on the Forced Ventilation Safety during the Construction of a Large-Slope V-Shaped Tunnel Applied Sciences V-shaped tunnel under construction experimental study forced ventilation construction environment tunnel structure |
title | Experimental Study on the Forced Ventilation Safety during the Construction of a Large-Slope V-Shaped Tunnel |
title_full | Experimental Study on the Forced Ventilation Safety during the Construction of a Large-Slope V-Shaped Tunnel |
title_fullStr | Experimental Study on the Forced Ventilation Safety during the Construction of a Large-Slope V-Shaped Tunnel |
title_full_unstemmed | Experimental Study on the Forced Ventilation Safety during the Construction of a Large-Slope V-Shaped Tunnel |
title_short | Experimental Study on the Forced Ventilation Safety during the Construction of a Large-Slope V-Shaped Tunnel |
title_sort | experimental study on the forced ventilation safety during the construction of a large slope v shaped tunnel |
topic | V-shaped tunnel under construction experimental study forced ventilation construction environment tunnel structure |
url | https://www.mdpi.com/2076-3417/14/7/2924 |
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