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Environmental aspects of underground construction and exploration for underground structures—State-of-the-art
Published in Wang Sijing, Fu Bingjun, Li Zhongkui, st Century, 2020
Sebastiano Pelizza, Pier Paolo Oreste
In a tunnel, the ground acts not only as the loading mechanism, but also as the primary supporting medium. Think of it this way; when the excavation is made, the strength of the surrounding ground keeps the hole open until the tunnel supports are installed. Moreover, even after supports are in place, the ground continues to provide a substantial percentage of the total load-carrying capacity through arching. Thus, for the tunnel designer and builder, the rock or soil surrounding a tunnel is effectively a construction material.
Ventilation applied to fire safety in metro tunnels, Naples line 1 project
Published in Daniele Peila, Giulia Viggiani, Tarcisio Celestino, Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 2020
Focusing on the longitudinal ventilation, it can be sub-categorized into pure longitudinal ventilation e.g. by means of jet fans only and longitudinal ventilation generated by exhausting air/smoke at one or more points along the tunnel eventually aided by jet fans. Pure longitudinal ventilation mode is typically applied in road tunnels. For underground metro lines, the smoke extraction ventilation mode (longitudinal) must be applied, eventually integrated with jet fans, mainly because it is mandatory to effectively remove smoke and evacuate it at the street level. For this reason, for all tunnel sections between two stations, at least one fan room must be foreseen. Lastly, special constructions can be designed inside the tunnel to mitigate the effect of fire and smoke flows, such as emergency exits, cross-passages and rescue stations.
Ventilation applied to fire safety in metro tunnels, Naples line 1 project
Published in Daniele Peila, Giulia Viggiani, Tarcisio Celestino, Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 2019
Focusing on the longitudinal ventilation, it can be sub-categorized into pure longitudinal ventilation e.g. by means of jet fans only and longitudinal ventilation generated by exhausting air/smoke at one or more points along the tunnel eventually aided by jet fans. Pure longitudinal ventilation mode is typically applied in road tunnels. For underground metro lines, the smoke extraction ventilation mode (longitudinal) must be applied, eventually integrated with jet fans, mainly because it is mandatory to effectively remove smoke and evacuate it at the street level. For this reason, for all tunnel sections between two stations, at least one fan room must be foreseen. Lastly, special constructions can be designed inside the tunnel to mitigate the effect of fire and smoke flows, such as emergency exits, cross-passages and rescue stations.
Study on structural mechanical characteristics and safety warning of NATM tunnel in aquifer
Published in Marine Georesources & Geotechnology, 2022
Binke Chen, Zhiqiang Zhang, Yinjun Tan, Yiwei Liu
Developed countries, notably Japan, Norway, Denmark, Britain, France and China, have been building subsea tunnels since the 1930s. Prominent projects include the Seikan Subsea Tunnel of Japan, Channel Tunnel of Britain and France, Subsea Tunnel of Norway, Xiamen Xiang’an Subsea Tunnel and Lion Ocean Subsea Tunnel of China (Chen et al. 2013; Cui and Fu 2004; Gu, Zhu, and Zhong 2004; He and Liu 2018; Li et al. 2016; Samuelsen and Grov 2018; Wei, Qiu, and Wei 2014). However, relative to the channel tunnel project development, the corresponding design theory lags behind the engineering construction. Researchers worldwide have been attempting to solve problems such as tunnel lining structure under the action of soil and water pressure characteristics and structure of security monitoring, assessment, early-warning and other technical systems (Bossi, Schenato, and Marcato 2017; Liu et al. 2022; Sun 2006; Ye, Ni, and Yin 2013; Zhou, Su, and Wu 2015).
Crash analysis of expressway long tunnels using a seven-zone analytic approach
Published in Journal of Transportation Safety & Security, 2021
Amjad Pervez, Helai Huang, Jaeyoung Lee, Chunyang Han, Jie Wang, Xuan Zhang
Tunnels, as a part of expressway network, have contributed to reduce travel time, protect ecological environment, and play a significant role in the expressway operation. The limited inner space and confined environment of expressway tunnels make it hard to rescue and evacuate people in the event of crash. Particularly, for a crash resulting in a fire, the consequences can be more severe due to the expansion of heat and smoke (Amundsen & Ranes 2000; Ma, Shao, & Zhang, 2009). In recent years, the number of expressway tunnels has significantly increased resulting in an increase in tunnel traffic crashes. For example, the number of expressway tunnel crashes in China increased from 244 to 305 between 2012 and 2016, resulting in 685 fatalities, making up to 60% of all road tunnel fatalities, according to the Institute of Traffic Management Science, Ministry of Public Security of China (2017). Therefore, it is essential to examine the crash characteristics of tunnels to find effective measures to improve the tunnel safety.
Mega infrastructure as a dynamic ecosystem: Lessons from America’s interstate system and Boston’s big dig
Published in Journal of Mega Infrastructure & Sustainable Development, 2019
Virginia A. Greiman, Elliott D. Sclar
As a case in point, consider the Channel Tunnel, the longest underwater rail tunnel in Europe, connecting the United Kingdom and France. This project was originally promoted as highly beneficial both economically and financially. However, the reality is much different. Capital costs went 80% over budget, and financing costs 140%. Revenues started at a dismal 10% of those forecast, eventually growing to half of the forecast. This drives home an important point. A megaproject may well be a technological success, but a financial failure, and many are. An economic and financial ex post evaluation of the Channel Tunnel, which systematically compared actual with forecast costs and benefits, concluded that “the British Economy would have been better off had the Tunnel never been constructed” (Anguera, 2006, p. 291). (Flyvbjerg, 2017).