Underground localization of public utilities are described in examples of the utilization of rock formations and soft ground. The advantages of using the underground freely are outlined: i.e. a rational use of the "Terra space" to enhance public services to economic and long-lasting solutions without interference with the environment above ground. The use of the underground is of growing importance in rapidly expanding cities, where underground locations may be the only choice. There are, however, special effects of going underground which have to be taken into account, like the sterilization of the use of underground for other purposes and the risk for conflicts, if there is no planning and mapping of the space below us.
This report will concentrate on underground applications for public utilities, viz:-
-electricity and telecoms
Also defense and public transportation utilities go underground, but they win not be included in our contribution. With the exception of solid wastes, the public utilities mentioned above, already go underground as a matter of course in all planning. However, in most cases the underground planning mode mostly reflects the surface plan. Pipes, ducts and cables follow the streets in a more.or less rigid system. We will here aim at describing the use of the underground space in a more flexible way, i.e. irrespective of surface structures. By a free utilization of the underground, be it soft ground or rock, the full advantage can be taken of the so called "terra-space", or the ground beneath our feet. The cities are seldom or never located with respect to a suitable underground for our public utilities. It has rather been trade and defense aspects that have dominated the location and further development for our cities. Therefore the underground engineering, "Tiefbau" - as the Germans say - has encountered technical difficulties such as:-
-river sediments of heterogenic composition
-groundwater and surface water problems
-bedrock at varying levels and with varying quality
There is technique available to overcome these difficulties in soft ground or in rock, as will be shown in the subsequent examples from different parts of the world, mainly our native countries England and Sweden. It would certainly be bad economy, if the use of the underground would be restricted because of lack of experience by the planners. The underground invites to a more daring attitude to non-conventional solutions than surface planning. It will not be admired by the great public which may not even be aware of it. It is a science for experts to appreciate. The use of the underground is manifold. Public utilities have a long standing for being transferred.to the underground, but even between them there may be conflicts. Surface planning has a normal restriction in ownership of land which underground planning in its wide sense has not. We wilt revert to this at the end of this report. Up to the present the first user to come around will have the possibility to use the underground almost freely.