How can the use of underground space accommodate the complex demands of today’s society while improving urban sustainability and microclimate?
Enes Osmani_18006757_Urban Sustainability & Microclimates_ P30402
CONTENTS
1 Introduction
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History of urban underground spaces
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Reviewing existing knowledge
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Environmental benefits of urban under ground space use
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Current urban underground space use
14 Conclusion
15 References
INTRODUCTION
As urban areas grow in geographical size and population, the surface area available to accommodate this growth is diminishing rapidly. Estimates have put the current global population at 7.616 billion, with growth expected to be at 8.6 billion by mid-2030, 9.8 billion by mid-2050 and 11.2 by 2100. (United Nations, World Population Prospects, 2017). The rapid growth of the world’s population will require a significant increase in the development of new infrastructure. While at one point the highrise may have been one way of addressing this issue, what if a solution lies in the opposite direction? As a result of the growing population and increase in infrastructure, efforts will need to be made to contain urban sprawl and to densify further in the already built-up areas. This poses a threat to urban sustainability and microclimate.
Worldwide, the invaluable asset of urban underground space (UUS) is often overlooked with factors such as cost, technology, and existing urban fabric contributing to its complexity. Most cities and urban areas are unaware of the benefits that UUS can potentially offer, both in terms of environmental and spatial opportunity. However, surface land in urban areas can be used more effectively by moving certain facilities and functions underground. Not only would UUS put less pressure on surface area demands, but will also benefit cities by assisting in reducing pollution and moderating the urban heat island effect. It will have a direct positive impact on urban sustainability and microclimate. The United Nations Environment Global Status Report (2017) showed that buildings and transport are a major driver of energy demand and global CO2 emissions (see Fig. 01).
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Fig. 01: Buildings & transport are a major driver of energy demand and global CO2 emissions.
This paper seeks to investigate how the use of underground facilities can accommodate the complex demands of today’s society while improving urban sustainability and microclimate. Firstly, through investigating the history of urban underground space. Secondly, analysing research that has been conducted on UUS and how UUS can reduce pollution and moderate the urban heat island effect. Lastly, analysing various current developments as case studies where underground space has been used as a solution to an issue on the surface environment.
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HISTORY OF URBAN UNDERGROUND SPACE
During the industrial revolution, underground space was perceived as a negative place where factory workers were housed in cold, damp, poorly ventilated basements and cellars (Meijenfeldt, Geluk and Vatter-Buck, 2003). The concept of UUS as a means of accommodating transportation emerged towards the end of the 18th century when the first underground mass transit systems were built. The earliest metro system was constructed in London in 1863, as a solution to the problem of horse-drawn traffic at the time (Besner, 2017). Prior to this event, cities used very little underground space. Historically, the use of underground space in urban areas has not been actively planned; it was more of a space that has been used reactively when cities tend to respond to issues.
French architect and urban planner Eugène Hénard proposed an organised approach to UUS by essentially ‘burying’ urban traffic, utilities and goods in multi-level galleries (see Fig. 02). The idea was to reduce street traffic allowing for better pedestrian amenity and cleaner air (Admiraal and Cornaro, 2016). For the first time, underground space was perceived as a solution to an urban issue and was a principle that could be utilised for years to come.
Fig. 02: Eugène Hénard’s underground solution for Chicago, Illinois 3
Eugène Hénard inspired others to take further progressive steps towards UUS development. For instance, French-Armenian architect Édouard Utudjian reinforced the concept of "underground urbanism". In 1933 he established GECUS - the world’s first group dedicated to the study of life underground and the future of cities (de Balsac, 1985). It is clear from the work of the architect Édouard Utudjian in Figure 03 that he viewed the UUS as a significant asset to the city. He buried most of Paris entirely underground and left a clean, natural, healthy-looking environment above ground.
Fig. 03: Édouard Utudjian’s underground vision for Paris for the year 2000.
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However, in contrast, the notion of UUS was rejected as a solution to relieve traffic congestion by modernist architect and urban planner Le Corbusier (Besner, 2017). He put car ownership at the forefront of his plans, with high-rise blocks set in open green spaces connected by highways (see Fig. 04).
Fig. 04: Le Corbusier’s unrealised plan for Ville Radieuse.
The historical analysis reveals how cities developed over time, and the issues that pertained then are still issues we face today.Various architects and urban planners put forward their approaches to tackle issues such as congestion and pollution, some were fictional, some were successful, and others were unsuccessful. However, any development that has taken place has brought us to the current situation, congestion and pollution are still an issue worldwide, and if not addressed they will continue to be an issue for many future generations to come.
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REVIEWING EXISTING KNOWLEDGE
Recent global challenges such as population growth, climate change, and pressures on surface land, have increased research conducted on the use of UUS (Bobylev and Sterling, 2016). For this case study, I look at research by Antonia Cornaro and Han Admiraal of the Amberg Engineering Group in Zurich, Switzerland. Both are members of the TDUK think deep panel which is a group of professionals in the built environment promoting the use of UUS (Think Deep UK, 2018). In 2017, Cornaro and Admiraal published a paper which looks at sustainable urbanisation through underground development. The paper analysed several case studies; some of these case studies are mentioned in this essay. Based on these case studies Cornaro and Admiraal developed a sustainability framework which underground space projects need to meet if they are to contribute to sustainable development of cities and urbanising regions (see Fig. 05).
Fig. 05: Sustainability framework for UUS developed by Cornaro and Admiraal.
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They explain that when considering an underground project, the following aspects need to be included in the decision-making process: vision and strategy, planning and management.
Vision and strategy: “By integrating the underground spaces into the surface fabric, the underground becomes an integral part of that fabric. It no longer is a stand-alone monofunctional development; it starts to become part of the liveable and loveable city that is so important to us as urban residents.” Planning “The vision and strategy developed by a city should provide a solid basis to proceed on. Planning is required to take this a step further by ensuring that urban underground spaces become part of cities’ master plans as was done by the City of Helsinki.” Management “Once cities start to use their underground space, this space needs to be managed. Management of the underground space is needed to ensure that future generations will still be able to use it. As such it is essential to know what is happening in the subsurface beneath the city.”
Through the work of Antonia Cornaro and Han Admiraal, it is evident they see a need for the effective and long-term use of underground space in making cities more resilient, liveable and sustainable. They demonstrate through several case studies the potentials of UUS if executed with a clear vision and successful planning and management.
Another notable study was conducted by Shimizu Corporation, one of the largest construction companies in Japan. Shimizu entered a planned research collaboration with the University of Minnesota intending to enhance academic activity and understanding of underground space. In 1987 Shimizu donated a professorship to Professor Raymond Sterling and John Carmody to promote the study of underground space. The results of which are published in the book ‘Underground Space Design’. The book gives detailed information 7
about underground space design and is organised into two parts. Part one, researched by Raymond Sterling gives an overview of subsurface space utilisation. It looks at the benefits and drawbacks of underground facilities, the different classifications and the historical development and current use of underground space. Part two, researched by John Carmody looks at the layout and spatial configurations, interior design elements, lighting, and the psychological and physiological effects in underground space.
Sterling and Carmody write in their book: “While the focus of the book is on people in underground space, this should not be taken as implying that having people work or stay underground is ideal. Similarly, the use of underground space is also not a goal in its own right.�
Cornaro and Admiraal, Sterling and Carmody all share a common view that underground space is an integral part of the urban context. The studies mentioned provide extensive insight into the use of underground space and what it can offer in terms of environmental and spatial opportunity. However, underground space in itself does not lead to sustainable development and is not always an ideal option.
There is a gap in research that exists regarding the performance of UUS and energy consumption concerning lighting and ventilation (Qiao et al., 2019). There is also room for further study that looks at the effects of UUS on the geologic, ground and surface environments.
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ENVIRONMENTAL BENEFITS OF URBAN UNDER GROUND SPACE USE
By relocating transportation facilities underground like the example of the Boston Artery Project, surface land is freed up allowing for green spaces and plants. Below is a list of various other infrastructure that can be relocated underground to release land for other uses (Sterling et al., 2012). Green spaces and plants can be introduced in more areas on the surface environment.
• Commercial and institutional buildings • Car parking • Sports facilities • Community centres • Libraries • Office buildings • Educational institutions • Industrial facilities • Military and civil defence facilities • Energy production and storage • Utilities
Relocating transport and other various infrastructure underground is not feasible in every case. However, it is one solution to gaining land on the surface environment in order to create green spaces and plant more trees and vegetation. This is essential as plants are used to moderate the heat island effect. Urban heat island effect is a man-made area that’s significantly warmer than the surrounding rural area - especially in the evening (Met Office, 2012). Plants moderate heat islands through shading, evapotranspiration and wind shielding (Gartland, 2008). 9
• Shading: Plants moderate heat island effect by shading buildings, roads and pavements from the sun. This reduces surface temperatures which reduces the amount of heat transferred into the air. • Evapotranspiration: Air temperatures are cooler around well-vegetated areas because of evapotranspiration. Plants use the energy from the sun to evaporate water, preventing it from heating the environment. • Wind shielding: Depending on the density of the canopy, plants can reduce wind speeds by up to 20-80 per cent. Slower wind speeds mean less heat is convected away from buildings. • Plants also contribute to improving the urban microclimate by absorbing CO2 from the atmosphere during the process of photosynthesis; carbon is absorbed and is emitted as oxygen back into the atmosphere. Trees remove pollution from the air by absorbing harmful particles through their leaves. • Plants reduce the volume and rate of stormwater that hits the ground by catching rainfall on their leaves, branches and trunks. • The addition of plants to urban areas can introduce birds animals and insects. The quality of there habitats can be improved if a selection of native plant species is introduced to the urban landscape.
This analysis supports the importance of green spaces and plants in the urban context. Where possible, the relocation of existing infrastructure underground can create opportunities for new green spaces and plants on the surface environment. This is important as plants aid in the removal of pollutants, moderating heat island effect and improving the urban environment.
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CURRENT URBAN UNDERGROUND SPACE USE
With urban sprawl and rising land values becoming a significant problem, underground space becomes an attractive alternative often leading to successful developments (Paul, Chow and Kjekstad, 2002). On a global scale, UUS has taken time to gain interest amongst governments, urban planners and architects. There are many examples of cities that have successfully incorporated UUS in their city planning. For example, Montreal is commonly referred to as “The Underground City� with its interconnected underground central business district (see Fig. 06). In Tokyo, Japan there are examples of various programs interconnecting underground such as the Yaesu shopping mall, opened in 1969 on the east side of Tokyo Station. These examples improve the experience for peope using the facilities by providing better connectivity and a richer experience of the urban context.
Fig. 06: Underground city, Montreal.
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In other instances, elevated highways and railways are demolished to generate new life on the surface environment. For example, the Boston Artery Project rerouted one of the United States most congested highways underground. The project improved the quality of life in the city by creating forty-five new parks and landscapes, 900 newly planted trees, and new public plazas emerged (see Fig. 07). As a result of the project, air quality has improved in Boston; the city saw a 12 per cent reduction in carbon monoxide levels (Mass.gov, 2018).
Fig. 07: Boston, Massachusetts, before and after highway removal.
Similarly, another example of moving transport routes underground to accommodate more green space above is the rerouting of The M30 highway in Madrid to alleviate congestion, improve traffic flow, reduce travel time and significantly reduce the environmental and acoustic impact. In 2004 the city embarked on a ÂŁ3.5bn scheme which would see the highway rerouted through tunnels. As a result, the city gained one million square meters of green public space by placing 56 km of the 99 km long M30 motorway underground (Cornaro and Admiraal, 2017) 12
Furthermore, The Alaskan Way Viaduct in Seattle, Washington was formally a doubledecker highway that travelled along the western coast of Seattle. The rerouting of the highway underground has had a positive impact on re-establishing relationships with local neighbourhoods that were previously cut-off by the existing elevated highway. When complete the scheme will provide opportunities for green spaces along the waterfront and is expected to improve air quality (Cornaro and Admiraal, 2017). The effect of the underground solution can be seen in Fig. 08 and Fig. 09.
Fig. 08: Alaskan Highway, situation with elevated structure.
Fig. 09: Alaskan Highway, situation with bored tunnel.
These examples show how relocating transportation infrastructure underground can create opportunities for green space. This allows for various improvements in the way the city functions and also in its environment. 13
CONCLUSION
Overall, while there are challenges to building underground, with planning and resources, the research suggests the benefits outweigh the challenges. This essay encourages the idea that building underground works hand in hand with infrastructure on surface land. It reduces pressure on the surface land and can accommodate facilities that would otherwise contribute to polluting the environment. With the option for transport routes and facilities to be underground, this offers an opportunity for the surface environment to provide green spaces that improve urban sustainability and microclimate. To conclude, the subsurface should not only be viewed as a place to locate unwanted surface structures underground; it is about using a hidden yet valuable asset to enable urban areas to develop sustainably.
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REFERENCES
Books Gartland, L. (2008). Heat islands. London: Earthscan.
Meijenfeldt, E., Geluk, M. and Vatter-Buck, R. (2003). Below ground level. Basel, Switzerland: BirkhaĚˆuser-Publishers for Architecture.
Paul, T., Chow, F. and Kjekstad, O. (2002). Hidden aspects of urban planning. London: Thomas Telford.
Sterling, R. and Carmody, J. (1993). Underground space design. New York:Van Nostrand Reinhold.
Journals and Articles Admiraal, H. and Cornaro, A. (2016). Engaging decision makers for an urban underground future. Tunnelling and Underground Space Technology, 55, pp.221-223.
Bek, M., Azmy, N. and Elkafrawy, S. (2018). The effect of unplanned growth of urban areas on heat island phenomena. Ain Shams Engineering Journal, 9(4), pp.3169-3177.
Besner, J. (2017). Cities Think Underground – Underground Space (also) for People. Procedia Engineering, 209, pp.49-55.
Bobylev, N. and Sterling, R. (2016). Urban underground space: A growing imperative. Tunnelling and Underground Space Technology, 55, pp.1-4.
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Cornaro, A. and Admiraal, H. (2017). Sustainable urbanization through underground development – towards an urban underground future. [ebook] Available at: http://www.iasem.org/past_conf/asem17/Keynote/k0701F.pdf [Accessed 8 Apr. 2019].
de Balsac, R. (1985). The history of GECUS: A great adventure in contemporary urban development. [ebook] Available at: http://about.elsevier.com/media/tust-vsi/v9i5pp280-287. pdf [Accessed 8 Apr. 2019].
Global Status Report. (2017). [ebook] Global Alliance for Buildings and Construction. Available at: https://ec.europa.eu/energy/sites/ener/files/documents/020_fatih_birol_seif_ paris_11-12-17.pdf [Accessed 8 Apr. 2019].
Qiao,Y., Peng, F., Sabri, S. and Rajabifard, A. (2019). Low carbon effects of urban underground space. Sustainable Cities and Society, 45, pp.451-459.
Sterling, R., Admiraal, H., Bobylev, N., Parker, H., Godard, J.,Vähäaho, I., Rogers, C., Shi, X. and Hanamura, T. (2012). Sustainability issues for underground space in urban areas. Proceedings of the Institution of Civil Engineers - Urban Design and Planning, 165(4), pp.241-254.
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Electronic Resources Wsdot.wa.gov. (2019). Alaskan Way Viaduct - Home. [online] Available at: https://www. wsdot.wa.gov/projects/viaduct [Accessed 8 Apr. 2019].
Fr.slideshare.net. (2012). Edouard Utudjian & l’urbanisme souterrain. [online] Available at: https://fr.slideshare.net/archi-criture/edouard-utudjian-lurbanisme-souterrain [Accessed 8 Apr. 2019].
Mass.gov. (2018). The Big Dig: project background. [online] Available at: https://www.mass. gov/info-details/the-big-dig-project-background#the-problem- [Accessed 8 Apr. 2019].
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Images Fig. 01: IEA World Energy Balances and Statistics (2017). Buildings & construction energy demand and global CO2 emissions.. [image] Available at: https://ec.europa.eu/energy/sites/ ener/files/documents/020_fatih_birol_seif_paris_11-12-17.pdf [Accessed 10 Apr. 2019].
Fig. 02: Reps, J. (2010). Underground solution for Chicago, Illinois. [image] Available at: http://urbanplanning.library.cornell.edu/DOCS/henard.htm [Accessed 12 Apr. 2019].
Fig. 03: Privat, M. (2012). Édouard Utudjian’s underground vision for Paris for the year 2000. [image] Available at: https://fr.slideshare.net/archi-criture/edouard-utudjianlurbanisme-souterrain [Accessed 10 Apr. 2019].
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Fig 04: Archdaily (2013). AD Classics:Ville Radieuse / Le Corbusier. [image] Available at: https://www.archdaily.com/411878/ad-classics-ville-radieuse-le-corbusier?ad_ medium=gallery [Accessed 10 Apr. 2019].
Fig 05: Cornaro, A. and Admiraal, H. (2012). Sustainability matrix. [image] Available at: http://www.i-asem.org/past_conf/asem17/Keynote/k0701F.pdf [Accessed 10 Apr. 2019].
Fig 06: Getty Images (2019). Montreal’s Underground City. [image] Available at: https:// www.tripsavvy.com/underground-city-what-lies-beneath-downtown-montreal-4120917 [Accessed 10 Apr. 2019].
Fig 07: Parker, C. (2015). Boston’s “Big Dig” Highway project, before and after.. [image] Available at: https://thetokyofiles.com/2015/01/18/planting-rice-on-the-highway-ohashigreen-junction/boston-big-dig-before-after-photo-highway/ [Accessed 10 Apr. 2019].
Fig 08: Cornaro, A. and Admiraal, H. (2017). Alaskan Highway Seattle, USA. [image] Available at: http://www.i-asem.org/past_conf/asem17/Keynote/k0701F.pdf [Accessed 10 Apr. 2019].
Fig 09: Cornaro, A. and Admiraal, H. (2017). Alaskan Highway Seattle, USA. [image] Available at: http://www.i-asem.org/past_conf/asem17/Keynote/k0701F.pdf [Accessed 10
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