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Discussion on Operation Ventilation Design for the Super-long Subsea Tunnel of the Bohai Strait Channel
(1. School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750021; 2. School of Civil Engineering, Central South University, Changsha 410075)
Abstract The Bohai Strait Channel is a forthcoming mega-project in China that spans the Laotieshan Channel. The inability to set up intermediate ventilation shafts in the super-long subsea tunnel poses significant construction challenges. This paper recommends a combined supply and exhaust ventilation scheme with longitudinal ventilation,based on a comparative analysis of the economic feasibility and difficulty of overcoming obstacles in ventilation solutions for super-long subsea tunnels. The paper provides calculations for this ventilation scheme. First, it compares Chinese and EU tunnel ventilation design standards highlighting the mismatch between the baseline emissions in Chinese standards and current emission limits. It proposes a method to calculate the required air demand for the subsea tunnel based on baseline emissions under Euro 6 emission standards, detailing the design concentrations of pollutants used in the ventilation calculations and the considerations for canceling air exchange rates. Second, air velocity calculations inside the tunnel are conducted using both Chinese and EU standards, showing that the combined supply and exhaust with longitudinal ventilation scheme is feasible under normal traffic conditions. Finally, it discusses the shift in control indicators for tunnel ventilation design from pollutants like CO and dust to critical air velocity within the main tunnel, lithium battery fire control, and rescue ventilation indicators. The paper also examines the impact of an increased proportion of new energy vehicles on operational and rescue ventilation in tunnels, aiming to provide references for the Bohai Strait Channel ventilation design and improvements to China′s ventilation standards and emission regulations.
Abstract：
The Bohai Strait Channel is a forthcoming mega-project in China that spans the Laotieshan Channel. The inability to set up intermediate ventilation shafts in the super-long subsea tunnel poses significant construction challenges. This paper recommends a combined supply and exhaust ventilation scheme with longitudinal ventilation,based on a comparative analysis of the economic feasibility and difficulty of overcoming obstacles in ventilation solutions for super-long subsea tunnels. The paper provides calculations for this ventilation scheme. First, it compares Chinese and EU tunnel ventilation design standards highlighting the mismatch between the baseline emissions in Chinese standards and current emission limits. It proposes a method to calculate the required air demand for the subsea tunnel based on baseline emissions under Euro 6 emission standards, detailing the design concentrations of pollutants used in the ventilation calculations and the considerations for canceling air exchange rates. Second, air velocity calculations inside the tunnel are conducted using both Chinese and EU standards, showing that the combined supply and exhaust with longitudinal ventilation scheme is feasible under normal traffic conditions. Finally, it discusses the shift in control indicators for tunnel ventilation design from pollutants like CO and dust to critical air velocity within the main tunnel, lithium battery fire control, and rescue ventilation indicators. The paper also examines the impact of an increased proportion of new energy vehicles on operational and rescue ventilation in tunnels, aiming to provide references for the Bohai Strait Channel ventilation design and improvements to China′s ventilation standards and emission regulations.
XU Peng1 MA Zhenshuo1 WU Yimin2 WANG Zijian2 LIANG Weiming2
.Discussion on Operation Ventilation Design for the Super-long Subsea Tunnel of the Bohai Strait Channel[J] MODERN TUNNELLING TECHNOLOGY, 2024,V61(3): 45-52
2024, Vol. 61 