ESPACE SOUTERRAIN
was a non-profit organisation founded in 1988, today transformed in an AFTES-comittee gathering academics, city-planners, developers, civil engineers, geographers, geologists, lawyers, sociologiste, etc. in order to promote the use of subsurface space to elected representatives and other responsible persons in charge of the management of cities and to companies interested in building and operating underground facilities
ESPACE SOUTERRAIN
claims for inheritance from architect Edouard Utudjian, who defined the concept of Underground city planning, URBANISME SOUTERRAIN, through the organizations he founded and ruled, GECUS and CPITUS
ESPACE SOUTERRAIN
maintains close links with organisations working in the same fields, as :
ITA, International Tunnelling Association
AUCA, American Underground Space and Construction Association
ACUUS, Association of Research Centers for Underground Urban Space
French literature available on site : see french frames
English literature available onsite :
Conditions for the Emergence of an Indoor City, Ray STERLING ;
Present Condition
and Future of Indoor City, Takashi HIRAI
SITE RESERVATION POLICIES FOR LARGE UNDERGROUND OPENINGS
Pierre Duffaut, then ITA Secretary general, Rockstore Conference, Stockholm, 1977
Introduction Underground space was first considered as a precious resource under the most congested areas. Thanks to the third dimension, an extra degree of freedom was available inside highly built and highly indutrialized areas. In any place, the first project of burying an utility, or whatever function, could be developed without any other limitation than geology and private property. To the second one, the first project acted as an extra obstacle account of which had to be taken of, and so the problems become more and more intricate with the number of sucessive potential users. In spite of the possibility of superposition, by far freer than over ground level, a concept of urban underground planning has developed, through which the first project to be built ought to reserve space for the later ones. For instance, in a newly built city or city part, the project of an underground sewer will reserve the place for transit tunnels. But this kind of problems is not restricted to urbnan areas.
The aims of this paper are twofold : first to show examples of coexistence problems arisen between mine workings and civil underground works, as well as between ancient and recent works ; second to define a site concept for every use of underground space.
Underground, any project has to be worked out more carefully than on the surface, for any later alterations or enlargements will be more difficult. Of course, nothing can play the role of demolition, and restoring the initial state of the ground always is impossible.
As the geological conditions only provide a limited number of sites for large underground openings, except in a few favored countries, the best sites make up a precious resource, either at national or even at world level. By reference to ore bodies, such sites might be named storebodies.
Of course storage of goods is not the sole function of large underground openings. Many such functions are related to energy, as energy storage through hot water or comprssed air ; as energy saving by putting underground any kind of activities, and also with underground siting of nuclear power plants. Among functions not related to energy, focus has to be placed on undergroun shelters for defence, as the Norad radar plants in the USA and Canada.
1. Underground vicinity problems Interaction between mine workings close to each other ...
2. The site concept
Conclusions Up to now, few countries have developed bodies of laws governing all the possible uses of underground space. It is clear that every underground work has to be authorized and registered ; every hole must be traced on an official map. A number of underground works need to have their surroundings protected. And mostly, the sitesable to accommodate very large openings must be inventoriated, classified, and preserved.
GEOLOGY, LANDFORMS, AND SUBSURFACE USE PLANNING
Jacques Brégeon et Pierre Duffaut, Landplan Symposium, Bangkok, 1982
Abstract Subsurface provides nations with mineral resources and with space resources, the more where rock qualitty, rock structure, and landforms are favourable to underground works. The paper reviews the uses of this space for passage and shelter and lists the benefits and drawbacks of the subsurface alernative. At the national level, benefits are likely in environmental protection, economy of energy, and military and civil defense. Examples of specific uses of subsurface. Main policies of national subsurface in various places of Thailand and some other countries are proposed. Main policies of national subsurface use planning are to authorize and record any undesrground, to inventoriate the sites likely to accommodate specific uses, to establis an authority for the management of subsurface.
UNDERGROUND CITY NETWORKS
Pierre Duffaut & Monique Labbé, Espace Souterrain, ChongQing, 1997
ABSTRACT The subsurface of cities began with hosting utility networks, such as sewers and water ducts. Later in major cities, public transport needed bigger tubes for metros and roadways ; car parks have developed also, as well as many other uses. Most of these underground works have been planned one after one, as single purpose facilities, without any connection nor synergy. As each of them is to need repairs and extensions, the city soon faces problems of overcrowding. Today underground space use needs new policies in order cities take full benefit of their subsurface. Planning the utility networks may appear as the best model for planning the whole subsurface of the cities in the near future.
Introduction
The underground networks of «small» utilities are together the nerves of big cities, carrying energy and information, and their arteries and veins, carrying water, the very blood of any city. Most of them have long been embedded into the soil for preservation and efficiency, without too many aerial or surface crossings. Later, transportation of freight and people has asked for bigger and deeper tubes, for rail and road vehicles. Each authority in charge of a network has built it without any reference to later users ; the first one has taken the best place inside a virgin ground, and has expanded its facilities without any restraint, therefore leaving a «disabled» space for next uses (even for an extension of its own works). It is easy to understand that more than three networks were to turn into a maze within the first two meters of depth below the streets, but it looks difficult to understand how such a disorder has been tolerated up to now [1]. Also owners of buildings begin to think of the value of their subsoil, when there is no longer any space around to extend their activity or support extra services.
After giving a few examples, the paper suggests that the utility networks could be the first mesh for planning and developing the underground part of the city of tomorrow [2,3].
UTILIDORS From their construction, the Paris sewers were intended to host also water ducts, for both drinking and raw water ; as they were designed for being cleared by workers, a lot of extra space was available ; so they became the first utilidors, long before this word was born in the USA. Later they received gas ducts, electric wires, and compressed air pipes (Paris is the only city in the world served by this energy, used for clocks, mechanical shops and many tools, including in dental surgery) ; some of these networks left along time, some other ones were placed in trenches along streets, but new networks are now applying for a place inside the sewers, such as refrigerated water for air conditioning and TV cable. Nevertheless, most of gas ducts, electric wires and telephone networks are today in separate trenches below streets and pavements.
Few cities in the world do have an extensive network of so-called technical or industrial tunnels, hosting together most of utilities. On the contrary many authorities, such as university campuses, hospitals, recreation parks (Disney), military barracks, nuclear power plants, etc. have obtained that most of their ducts and wires follow the same paths everywhere convenient. Incompatibility problems are well known, as hazard of electric sparks igniting gas losses, or heat transfer between hot and refrigerated water, but they can be solved by adequate insulation.
Utilidor is more a concept than an object, which can be applied to a special tunnel, or to a part of a bigger tunnel, to a bridge caisson, to open spaces left in building basements, etc. Their main interest lies in easier maintenance and greater safety of visible networks, instead of embedded ones ; the main reluctance comes from the will of each utility to manage its own territory alone. Mayors must be strong enough to counteract this kind of egoism.
MULTISTOREY STREETS
As soon as the middle of the XIXth century, Chicago built 63 km of freight tunnels below the streets of its centre, to serve the basements of the first skyscrapers, before the advent of motorised trucks, which soon replaced the narrow gauge underground tracks. The first proposals for underground tracks inside Paris (1855) were also for goods between the railway stations and the central market place, «les Halles». In London too, an underground track 8 km long had been bored for carrying letters and packages between major offices of the Royal Post. In 1863 the first metropolitan railway opened in London between the main (surface) railway stations, East and West of the «City»; it was the first occurrence of a two-storey street, with trains below into a cut-and-cover trench.
In 1903, French architect Hénart [4] also designed a two-storey street with all ducts and wires below the pavement together with tracks for freight transport, with direct access to the basements, leaving the surface to walkers, tramcars, and automobiles, which were only very few at the time. Around 1920, architect Le Corbusier initiated the Athen’s chart, along which all the traffic is confined under a slab ; this model of city has been applied to limited wards of some cities (as in la Défense, close to Paris), Though it provides plenty of space for utilities, it has never found any enthusiastic support from inhabitants. However, the space below the slab plays the same way as a technical storey in a high rise building.
INTERCHANGE STATIONS
Connections between various transportation systems are easier where two or more levels are
provided : the main railway station of Marseilles (south of France) is a good example as the train level is on top of a hill, the metro lines 20 m lower, with car parks built underground in between. Superposition provides for shorter connections through lifts and escalators (mechanical stairs). On the contrary in la Défense (west of Paris) long walking distances are needed to go from a bus to a train, because different tracks are managed by different authorities and their stations have not been designed at the same time. A project is being now studied for better connections, through a big commercial centre.
The deep stations of the new EOLE express metro line (in construction in Paris) are the first ones truly underground with four tracks ; a part of them has been built in partnership with developers of commercial buildings on the surface.
PARIS LASER PROJECT (& MUSE PROJECT for the greater Paris)
Car traffic inside Paris caused concern as soon as in the twenties and projects of underground roadways date back from the same years. Architect Utudjian, founder of CPITUS (International permanent committee for techniques of underground urbanism) designed in 1936 a network limited to the Paris proper, but it proved too early. Ten years ago, in 1987 the contractor company GTM (Grands Travaux de Marseille) proposed a toll expressway network for light cars only (maximum height 2m). Thanks to this limit a two storeys tunnel may be accommodated inside a circular tunnel about 10 m internal diameter. Each half receives a one-way traffic along three lanes, one of them neutralised for cars entering or leaving. The network is made of a central loop plus radials connected to main surface expressways. Connections to the surface were about 10 inside Paris in order to bypass most of overcrowded quarters. Ways-out were served by long enough tunnels and 2 to 4 openings to prevent surface traffic jams to hinder the flow on the main expressway. Also underground car parks were to be connected to these access ways.
Such a road project, serving the whole city and the main suburbs, did not include any room for other utilities (telecommunications, water, gas and electricity mains, etc.), as its internal diameter did not provide much space, but it would have showed a way to improve at the same time more than one utility or function. Conversely some may think that it is not so good to place all the eggs in the same bag!
As the project has not been accepted by the inhabitants, the mayor failed to support it. Other schemes of underground expressways are now under study, either around Paris or between Paris and Roissy airport. The most interesting is for the western suburbs : here the richest district in France supports a 40 km network, MUSE, which is supposed to host a mass transport system in addition to the roadways into a three storeys tunnel. Such a project emphasises the interest of putting together many uses into the same hole.
OTHER USES
It may be useful to briefly recall the extensive storage of goods in Kansas City underground quarries, the water treatment stations in major Scandinavian cities, as well as in the tiny Principality of Monaco, and the refrigerated storage (in Oslo and Bergen, Norway). Also many underground facilities ave been intended to receive people for social events, such as churches in Lourdes, France and Helsinki, Finland, theaters and sports halls in Scandinavia, and the biggest cavern ever mined for the Gjövik skating ice ring (Norway, Winter Olympics 1992, spanning 61 m). Some exotic uses could be cited too, as air conditioning in Chongqing.
MULTIFUNCTION VOLUMES
Just as for the tubes of utility networks, most of these caverns serve only one function. But some cases provide dual functions or more : after many commercial centres located underground in connection with railway and metro stations (most of them in Canada and Japan), the Japanese designers have proposed huge underground caverns below cities (along the European myth of Alice in wonderland). Here is presented an alternative to a single function project : a multipurpose car park under a street of central Paris.
Fig. 1 : Cross section of a multifunction car park under a street
translations : îlot = block ; galerie technique : multinetwork gallery (utilidor) ; parc de stationnement public = public car park ; caves, réserves = basements,
desserte, quai de déchargement = loading-unloading area and quay
HILLS INSIDE CITIES
Where available, hills provide great value underground space for cities. Salzburg, Germany, and Scandinavian cities offer many examples, as well as Kansas City, USA, referred to earlier. Level access to such space is likely, and even gravity may help going out when a car motor does not work. Hillside car parks are many in Germany, the Norwegian skating ring quoted above shares a hill with a swimming hall and many other facilities.
A Canadian study [5] depicts a 3 dimension allotment of the volume of a hill closing the harbour of Saint John’s, Newfoundland, Canada. Five stories of caverns are designed for various uses, from storage at the lower levels to industry, commerce, and then university rooms on top (the extracted rock being used for new dykes to close a bigger harbour outside of the previous one). The celebrated «sugar loafs» of Rio de Janeiro could provide huge caverns likely to host industrial plants including for power generation, even nuclear ones. The city of Chongqing, China, may benefit from its relief to bore many tunnels and caverns. In any case, as has been pointed out before, the first projects must be part of a long run planning scheme, in order future uses be not hindered.
PROPERTY RIGHTS
Property of land usually is parted along lines making a 2 dimensional scheme ; along the laws of ancient Rome property rights extend vertically from the surface, upwards and downwards, indefinitely (ad caelos et infernis, to heaven and to hell). A beneficial use of underground requires that property become 3 dimensional, with other partings along horizontal surfaces (or even more intricate surfaces).
Many rules limit the rights of construction over the surface, therefore the use of property rights to the heaven no longer exist anywhere. Below the surface, the same will apply : just as for the air over the city, the rights on the subsurface of a city must be equally shared by all citizens and all authorities (the State, the City, national, regional and local companies of transport, water, sanitation, electricity, and telecom).
Suburbs and subsurface Space
Suburbs is a word applied to the surroundings of a big city (Latin urbs = city), providing for all what is not accepted inside the city, due to lack of space (agriculture) or to nuisances (industry), and also low cost housing for low revenue people. The underground part of a city must not become a suburb (in spite of Latin word sub meaning below), but it can host all what can be removed from the surface in order to leave more space for people. Most of suburbs have developed in an uncontrolled way, what is no longer thinkable for the subsurface of a city. In conventional cities up to now, only marginal quarters are close to the suburbs, in the «thick» city, availability of suburban functions will be the same everywhere, even in the centre
CONCLUSIONS
Cities have to grow in thickness, not so much towards the sky as they did in the time of skyscrapers, but plenty of space is available downwards, provided some provisions be made to reserve the best sites for the biggest caverns [6], and to save access to deeper space.
Even if underground space may appear unlimited, uncontrolled uses may waste too much of it, whatever for tiny ducts or expressway interchanges. Giving a value to any volume of space may help spare it and use it in the best way.
When a hole is to be bored, it may accommodate more than the first project, with or without some enlargement. So road tunnels may accommodate wires and ducts, as bridges use to do. So some expressway tunnels may accommodate mass transit vehicles for a better service of the community needs. If a hole may accommodate more users, it must do that [7], as it has been only practiced up to now in Brussels, Belgium, through the collaboration of various ministries. Never more any underground facility must be planned without being multi- purpose.
Whatever the property rules in a country, the volume of ground below a city is de facto a joint ownership of all the citizens and their authorities, just as the walls, foundations and roofs are shared by all owners of flats in a multiflat building. The true interest of any city is to find the balance of public and private interests. This requires, in the long run, that subsurface use be thoroughly planned. Mayors of cities do have this responsibility.
French metros : Construction costs vs. transport social costs
Jean-Paul Godard & T. Lequeux, Tunnels ans Metropoliese, Sâo Paulo, 1998