Outlook For Faster Tunneling

Tunneling is at the threshold of a new era. An exciting new technology is becoming available. And, supplying the increasing quantities of minerals required by a growing and socially advancing world population, together with providing the subsurface facilities attendant to the rapid urbanization of the more developed countries of the world, will require underground excavation during the next decades on a scale that would have seemed fantastic a few years ago. It is estimated that world mineral consumption will increase fivefold by the year 2000. Projections for the United States indicate that domestic consumption of nonfuel minerals may increase two to three times by the end of the century. Meeting these requirements will entail opening up many new underground mines, even if present trends toward surface mining continue. And, at least in the United States, new factors that are becoming increasingly important may modify these trends. We are depleting our shallow easy- to-find and easy-to-mine mineral deposits; and, if we are to avoid becoming dangerously dependent on imports, we must turn more and more toward deeper deposits that are not amenable to surface mining. Growing public concern with environmental quality is apparently leading toward increasingly stringent regulation of surface mining which also will tend to make underground mining economically more attractive. The world market for underground construction is also growing rapidly. The most conservative projections indicate that in the United States alone more than $7.0 billion will be spent on excavation for underground facilities during the next ten years. And these estimates do not include any of the bold, imaginative new applications for underground excavation that have been proposed, such as extensive underground power transmission, the Chicago Deep Tunnel plan, and the Northeast Corridor Transportation project. There can be little doubt then that the market for tunnels for conventional applications is increasing rapidly and that the trend will continue. It