童叟无欺Sustainable Development of Urban Underground Space for Utilities
(J.J.Cano-Hurtado and J.Canto-Perello)
Abstract: The authors examine the us of multi-purpo utility tunnel systems in urban areas as a technique for solving problems of congestion in the shallow underground. Several underground developments in Europe are mentioned. The Utility Tunnels European Rearch Group (U.T.E.R.G), founded by the National Institute for Urban Engineering of France and the Polytechnic University of Valence in Span, was established to rve as a focal point for rearch on utility tunnels in Europe. This group’s mission and potential rearch topics are elaborated.
简单小制作
如何制作酸菜Key words: Public Tunnel; Sustainable Development; Underground Space
1飙车电影、 Introduction
During the nineteenth century, "nets" of urban rvices extended beyond the space defined by the administrative barriers, to create their own territory. This territory was neither longer
alveolar like that of the medieval city, nor reticulated like the new industrial city; rather, it formed a territory dominated by the net of rvices. And this is the new space of urban engineering, in which the nets are not only infrastructure but also are the main elements in the ordination of the city, creating a new urbanism: the “urbanism of the nets” (Dupuy 1996).
1979年什么命In our cities, nearly all of the underground space down to 2 meters beneath the pavement level is filled with urban utilities. In narrow streets like tho found in European historical towns, so they have to be placed clor together or above each other. This density of utilities has been ironically termed “the spaghetti subsurface problem” by urban engineers (Oude 1992). In our modern society we cannot live without utilities, and their number is growing. For this reason, the u of underground space for utilities is by far the most extensive u of the urban subsurface. Furthermore, the total cost of all types of urban utility systems in the developed Western world was approximately ＄US25billion per year in 1987 (Sterling et al. 1993).
All of the factors have led to an increasing interest in urban utility tunnel systems as a problem-solving technique for the effects produced by congestion of the shallow urban underground. This paper shows utility tunnels to be the most effective solution to achieve sustainable development of urban underground space. It mentions some underground utilities projects that have been adopted by veral European cities, and discuss the results of and future developments in urban engineering rearch, such as the creation of the U.T.E.R.G.(Utility Tunnels European Rearch Group), founded by the National Institute for Urban Engineering of France and the Polytechnic University of Valencia in Spain. This group is trying to rve as a focal point of rearch for all the institutions or companies dealing with utility tunnels in Europe. There are not many studies in this field, which offers great possibilities of development. The purpos of the rearch group are to:
●Collect information about existing knowledge；
●Exchange specialized bibliographies;
●Visit sites;
●Exchange experiences;
●Compare and contrast international experiences;
●Acquire and common and new techniques;
●Acquire new knowledge on technologies and management;
●Accelerate creation of a knowledge ba;
●Perform rearch studies.
2、Utility Tunnel
The u of utility tunnels to integrate urban rvices dates back to the engineers of the Roman Empire, who placed water supply conduits in the wage systems. An example of this technology can be found in the wers of Rome, with a huge cross-ction that is still
in u. This technology was forgotten during the Middle Ages, but was resurrected in 1855, when Haussman’s project for reforming the urban utility systems of Paris was approved. Haussman was a great admirer of Roman engineers. The Paris wage system was designed as a man-accessible tunnel and was capable of integrating other urban rvices. Since then, utility tunnels have been ud around the world, although not always in a proper way and not always in locations where it would be desirable.
It is not easy to define the term ”utility tunnel,” but the most striking feature of the systems is that they integrate urban utilities in an easily accessible space at any point of their length (Cano, et al. 1997).
Tunnel accessibility can be planned in two ways. On the one hand, the utility tunnel can be lectively accessible, but personnel displacement is not possible due to its reduced cross-ction: this type of utility tunnel is called archable. On the other hand are utility tunnels that can be person-accessible throughout their length: the tunnels are called visitable. The type of accessibility is perhaps the most important parameter for classifying
utilities tunnels, and it must be taken into account at the beginning of any such project. Searchable utility tunnels are ud to collect urban rvices in their last step of distribution, just before utilities connect to buildings. While visitable utility tunnels are commonly ud for transport of main utilities or when a huge cross-ction is necessary due to an elevated number of conduits to collect.
The main advantages of using utility tunnels are:
● to attain sustainable development of urban underground space;
● to avoid traffic interruptions on the surface;
● to aid in reliable arches of the subsurface utility works;
百合有什么功效● to prevent damage during construction works (utilities sometimes have to be moved or dug out temporarily to get to other utilities);
扣肉蒸多长时间● to free underground space for other purpos;
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● to reduce interference between urban rvices;
● to establish not only easily corrective maintenance procedures, but also predictive and preventive ones; and
● to encourage the coordination of works between companies.
The main disadvantages are that the management of the utility tunnels net is not as easy as it may look, and obtaining financing support for the projects is often difficult. In terms of initial costs, construction by trenching is cheaper, but if we take into account the maintenance cost, the renovation works, and the increasing importance of urban underground land value, utility tunnels are economically feasible. Urban underground land value is an interesting parameter to measure how efficiently resources have been allocated (Riera et al.1992). The less attention given to this value, the greater ”the spaghetti subsurface problem” will be.
