POTENTIALITIES OF THE URBAN VOLUME

....Betreuer:

Philippe Thalmann, Professor of Economics, EPFL Lausanne

Aurèle Parriaux, Professor Emeritus of Geology, EPFL Lausanne


Prüfungsexperten:

Prof. Vera Bühlmann, Department for Architectural Theory and Philosophy of Technics ATTP, TU Vienna

Prof. Dieter Dietz, Atelier de la conception de l’espace, Institute of Architecture, EPFL

Prof. Andres Sevtsuk, Department of Urban Planning and Design, GSD Harvard

Prof. Jérôme Chenal, CEAT, Institute of Architecture, EPFL

..

Betreuer:

Philippe Thalmann, Professor of Economics, EPFL Lausanne

Aurèle Parriaux, Professor Emeritus of Geology, EPFL Lausanne


Prüfungsexperten:

Prof. Vera Bühlmann, Department for Architectural Theory and Philosophy of Technics ATTP, TU Vienna

Prof. Dieter Dietz, Atelier de la conception de l’espace, Institute of Architecture, EPFL

Prof. Andres Sevtsuk, Department of Urban Planning and Design, GSD Harvard

Prof. Jérôme Chenal, CEAT, Institute of Architecture, EPFL

....

 

....Potentialities of the urban volume

Mapping underground resource potential and deciphering spatial economies and configurations of multi-level urban spaces

This dissertation looks at the urban volume, in its natural and artificial materiality, as a source of potential for future urbanization. Underground resources—for buildable space, geomaterials, groundwater and geothermal energy—tend to be addressed only as needs arise. This has historically led to conflicts between uses: basements and tunnels flooded by rising aquifers; drinking water sources endangered by infrastructures that carry pollutants into groundwater systems. The work was carried out as part of the Deep City Project, which argues for a paradigm shift of ‘resources to needs’ in which the potential of underground resources is addressed prior to any urban project or plan. The work presented here further develops a methodology to map the combined potentials of resources and includes an original investigation of the spatial relationships between underground and surface urban commercial spaces.

The prologue introduces the overarching problematic and concepts using a dramatization of an incident that occurred during the construction of the M2 metro line in Lausanne in 2005. This concrete example sets the stage for the first chapter, where the theoretical framework of the dissertation is laid out in detail. The resources to needs paradigm is elaborated by looking at the underground as it has been addressed in normative city models, arguing that the dominant ecological and mechanical models do not provide the adequate framework for thinking resources prior to needs. This reflection draws on concepts from information and urban theory as well as philosophy, arguing for an approach to the mass of the urban volume as an economy of communication—of encounter and avoidance.

The second chapter specifically addresses underground space through a spatial configurational analysis of the Montreal downtown, where a network of indoor and outdoor commercial spaces comprises a unique spatial volume. Relationships between the spaces are calculated using multiple accessibility metrics on a 3D spatial network model built in GIS. Common configurational characteristics are extracted using principal component analysis and placed in a spatial econometric model, which looks at the influence of spatial configuration on rental value per square meter of food and retail spaces. The results suggest that certain accessibility metrics contribute more than others to this value, but a subsequent geographically weighted regression reveals that this impact is varied in space and does not establish a clear separation between indoor and outdoor spaces.

The third chapter presents the application of the Deep City mapping method to three case study cities—San Antonio, Texas, Hong Kong, China, and Dakar, Senegal—which have relatively diverse and complex relationships to their geology and surface urbanization. In each case, adjustments are made to the methodology, particularly in how the potential of the surface urban form contributes to the underground potential of the city. The results of the maps, which provide a city-wide overview of underground potential, are discussed by returning to some of the projects and problematics currently addressed by each city’s urban planning departments or master plans. The conclusion summarizes the research as a whole and revisits the theoretical framework in discussing future avenues for research and practical application.

Keywords: urban morphology, GIS, urban diagnostic tool, Dakar, San Antonio, Hong Kong, Montreal, spatial econometrics, analytic hierarchy process, spatial network analysis.

 

here is an excerpt from the thesis:

prologue: rhythms interrupted

Lausanne. Tuesday, February 22, 2005. 6 p.m. Dinner at a fast food restaurant is interrupted by a man in hard hat, boots covered in mud, out of breath. Ovens switched off. Half-prepared burgers left on the counter. At a shopping market next door, the filling of grocery carts and baskets is interrupted by a hurried announcement inviting customers to come immediately to the registers.

The mundane on hold. Everyone out. Minutes earlier the work of a header machine boring without problem through molasse and moraine beneath the Place Saint-Laurent is interrupted by a sudden and unexpected flow of water-laden clay loam and gravel sands—remains of a glacial lake itself interrupted long ago by progressive peat infill and later sealed off beneath the public square. The tunnel gradually fills with mud and a cavity begins to form. The pavement—whose stability no passerby would have questioned several minutes earlier—is now only a 30-centimeter crust spanning a cavern estimated to be nearly 1000 cubic meters. The following twenty-one days are a fight to return to stability. The river of mud is contained. Building foundations and façades are reinforced. Construction workers are fed and warmed in the bitter cold of winter. The worries of local residents are assuaged. Several weeks later the ordeal is over. On the 18th of June in front of the Saint-Laurent church, the rhythms of a concert band celebrate a return to the rhythms of everyday life. The tunnel work can continue. The flows of the glacial lake have once again been silenced.1

The glacial lake is a forgotten mass. It was an interruption, noise on a channel. It was born of a chance turn of events. The departure of glaciers millions of years ago left a depression in which water collected, interrupted from its descent in the Lake of Geneva by a natural dam of impervious moraine.2 It is a stock of time. Pollen grains suggest that, 12,000 years ago, the boggy lake was surrounded by birch and willow trees. Evidence of human settlement suggests that the lake was also a place over 6,000 years ago where passages were interrupted, where one day trees were cleared and wheat was planted. This archive is interrupted by today’s building foundations, but at some point the glacial lake was no longer a reservoir of value. Situated on one of the important paths in Lausanne leading from Rome to Paris, it was paved over.3 The glacial lake was no longer a place where people wanted to encounter its boggy ground. By the 10th century, on solid ground nearby, a church was built, marking a spot connecting the mundane to the divine.

Marking a place to stop.4 A new kind of encounter. The street outside was not just a place of passage, channeling people from the Place de la Palud out the gates of the city towards France. That channel also sorted encounters. Peddlers, eventually shopkeepers, sold their wares. In some places more people passed—those were strategic places. Goods sold, services offered, quasi-objects for turning the traveler, quasi-subject, momentarily into a potential client. Other corners along the street were better for getting away from the crowd. Avoiding the noise, creating a calm. From passerby to patron.
The glacial lake is marked by chains of substitution—ice, water, swap, loam, foundation for the street—and as a mass has participated in other reconfigurations, as an informational motor. Its encounter with the header machine had the potential on that day in February to reconfigure the relationship between people, between the molasse and moraine and a mass of clay and loam, the continued possibility of passage. Yes, it could have been disastrous. That is the nature of its potentiality. We know from its own archive, that its potential has been actualized in different ways over time. Could it be any other way? Or do we continue to put the mass back in its place where we think it should be? We think we know the city because we’ve addressed it in so many ways. We’ve covered it in language and forgotten that the material is already the integral. Of all language—the logos. It is the mark of passage, of traces—of the graphein.

 

1 Luc Jaccard and Maurice Schobinger, M2: le défi (Lausanne: Editions Favre, 2008); Robin Marchant, “L’effondrement de St-Laurent,” Communiqué de presse (Lausanne, no date), https://www.unil.ch/mcg/fr/home/menuinst/pour-lesmedias/effondrement-de-st-laurent.html.
2 Marc Weidmann, Les dessous d’une ville: Petite géologie lausannoise, Les cahiers de la forêt lausannoise 2 (Lausanne: Direction des finances de la ville de Lausanne. Service des forêts, domaines et vignobles, 1987).
3 Louis Polla, De Saint Etienne Au Général Guisan: Louis Polla Raconte La Vie de Cent Personnages Qui Ont Donné Leur Nom Aux Rues de Lausanne (Lausanne: Editions 24 heures, 1981).
4 Jean Charles Biaudet, ed., Histoire de Lausanne, Univers de La France et Des Pays Francophones (Toulouse : Lausanne: Privat; Payot, 1982).

..POTENTIALITIES OF THE URBAN VOLUME

Mapping underground resource potential and deciphering spatial economies and configurations of multi-level urban spaces

This dissertation looks at the urban volume, in its natural and artificial materiality, as a source of potential for future urbanization. Underground resources—for buildable space, geomaterials, groundwater and geothermal energy—tend to be addressed only as needs arise. This has historically led to conflicts between uses: basements and tunnels flooded by rising aquifers; drinking water sources endangered by infrastructures that carry pollutants into groundwater systems. The work was carried out as part of the Deep City Project, which argues for a paradigm shift of ‘resources to needs’ in which the potential of underground resources is addressed prior to any urban project or plan. The work presented here further develops a methodology to map the combined potentials of resources and includes an original investigation of the spatial relationships between underground and surface urban commercial spaces.

The prologue introduces the overarching problematic and concepts using a dramatization of an incident that occurred during the construction of the M2 metro line in Lausanne in 2005. This concrete example sets the stage for the first chapter, where the theoretical framework of the dissertation is laid out in detail. The resources to needs paradigm is elaborated by looking at the underground as it has been addressed in normative city models, arguing that the dominant ecological and mechanical models do not provide the adequate framework for thinking resources prior to needs. This reflection draws on concepts from information and urban theory as well as philosophy, arguing for an approach to the mass of the urban volume as an economy of communication—of encounter and avoidance.

The second chapter specifically addresses underground space through a spatial configurational analysis of the Montreal downtown, where a network of indoor and outdoor commercial spaces comprises a unique spatial volume. Relationships between the spaces are calculated using multiple accessibility metrics on a 3D spatial network model built in GIS. Common configurational characteristics are extracted using principal component analysis and placed in a spatial econometric model, which looks at the influence of spatial configuration on rental value per square meter of food and retail spaces. The results suggest that certain accessibility metrics contribute more than others to this value, but a subsequent geographically weighted regression reveals that this impact is varied in space and does not establish a clear separation between indoor and outdoor spaces.

The third chapter presents the application of the Deep City mapping method to three case study cities—San Antonio, Texas, Hong Kong, China, and Dakar, Senegal—which have relatively diverse and complex relationships to their geology and surface urbanization. In each case, adjustments are made to the methodology, particularly in how the potential of the surface urban form contributes to the underground potential of the city. The results of the maps, which provide a city-wide overview of underground potential, are discussed by returning to some of the projects and problematics currently addressed by each city’s urban planning departments or master plans. The conclusion summarizes the research as a whole and revisits the theoretical framework in discussing future avenues for research and practical application.

Keywords: urban morphology, GIS, urban diagnostic tool, Dakar, San Antonio, Hong Kong, Montreal, spatial econometrics, analytic hierarchy process, spatial network analysis.

 

here is an excerpt from the thesis:

PROLOGUE: RHYTHMS INTERRUPTED

Lausanne. Tuesday, February 22, 2005. 6 p.m. Dinner at a fast food restaurant is interrupted by a man in hard hat, boots covered in mud, out of breath. Ovens switched off. Half-prepared burgers left on the counter. At a shopping market next door, the filling of grocery carts and baskets is interrupted by a hurried announcement inviting customers to come immediately to the registers.

The mundane on hold. Everyone out. Minutes earlier the work of a header machine boring without problem through molasse and moraine beneath the Place Saint-Laurent is interrupted by a sudden and unexpected flow of water-laden clay loam and gravel sands—remains of a glacial lake itself interrupted long ago by progressive peat infill and later sealed off beneath the public square. The tunnel gradually fills with mud and a cavity begins to form. The pavement—whose stability no passerby would have questioned several minutes earlier—is now only a 30-centimeter crust spanning a cavern estimated to be nearly 1000 cubic meters. The following twenty-one days are a fight to return to stability. The river of mud is contained. Building foundations and façades are reinforced. Construction workers are fed and warmed in the bitter cold of winter. The worries of local residents are assuaged. Several weeks later the ordeal is over. On the 18th of June in front of the Saint-Laurent church, the rhythms of a concert band celebrate a return to the rhythms of everyday life. The tunnel work can continue. The flows of the glacial lake have once again been silenced.1

The glacial lake is a forgotten mass. It was an interruption, noise on a channel. It was born of a chance turn of events. The departure of glaciers millions of years ago left a depression in which water collected, interrupted from its descent in the Lake of Geneva by a natural dam of impervious moraine.2 It is a stock of time. Pollen grains suggest that, 12,000 years ago, the boggy lake was surrounded by birch and willow trees. Evidence of human settlement suggests that the lake was also a place over 6,000 years ago where passages were interrupted, where one day trees were cleared and wheat was planted. This archive is interrupted by today’s building foundations, but at some point the glacial lake was no longer a reservoir of value. Situated on one of the important paths in Lausanne leading from Rome to Paris, it was paved over.3 The glacial lake was no longer a place where people wanted to encounter its boggy ground. By the 10th century, on solid ground nearby, a church was built, marking a spot connecting the mundane to the divine.

Marking a place to stop.4 A new kind of encounter. The street outside was not just a place of passage, channeling people from the Place de la Palud out the gates of the city towards France. That channel also sorted encounters. Peddlers, eventually shopkeepers, sold their wares. In some places more people passed—those were strategic places. Goods sold, services offered, quasi-objects for turning the traveler, quasi-subject, momentarily into a potential client. Other corners along the street were better for getting away from the crowd. Avoiding the noise, creating a calm. From passerby to patron.
The glacial lake is marked by chains of substitution—ice, water, swap, loam, foundation for the street—and as a mass has participated in other reconfigurations, as an informational motor. Its encounter with the header machine had the potential on that day in February to reconfigure the relationship between people, between the molasse and moraine and a mass of clay and loam, the continued possibility of passage. Yes, it could have been disastrous. That is the nature of its potentiality. We know from its own archive, that its potential has been actualized in different ways over time. Could it be any other way? Or do we continue to put the mass back in its place where we think it should be? We think we know the city because we’ve addressed it in so many ways. We’ve covered it in language and forgotten that the material is already the integral. Of all language—the logos. It is the mark of passage, of traces—of the graphein.

 

1 Luc Jaccard and Maurice Schobinger, M2: le défi (Lausanne: Editions Favre, 2008); Robin Marchant, “L’effondrement de St-Laurent,” Communiqué de presse (Lausanne, no date), https://www.unil.ch/mcg/fr/home/menuinst/pour-lesmedias/effondrement-de-st-laurent.html.
2 Marc Weidmann, Les dessous d’une ville: Petite géologie lausannoise, Les cahiers de la forêt lausannoise 2 (Lausanne: Direction des finances de la ville de Lausanne. Service des forêts, domaines et vignobles, 1987).
3 Louis Polla, De Saint Etienne Au Général Guisan: Louis Polla Raconte La Vie de Cent Personnages Qui Ont Donné Leur Nom Aux Rues de Lausanne (Lausanne: Editions 24 heures, 1981).
4 Jean Charles Biaudet, ed., Histoire de Lausanne, Univers de La France et Des Pays Francophones (Toulouse : Lausanne: Privat; Payot, 1982). ....