PLANNING AND DEVELOPMENT PII:S0886-7798(96) 00021-1 Going Under to Stay on Top, Revisited: Results of a Colloquium on Underground Space Utilization Raymond L. Sterling, Editor Abstract--This report summarizes the results of a three-day colloquium, held in Minnesota in July 1995, to address issues related to underground space utilization. The colloquium was convened by the Underground Space Center, with major support from the National Science Foundation, Directorate for Engineering, and the Federal Highway Administration. Since prehistoric times, humans have excavated cav- erns, tunnels, and other underground spaces for pro- tection, storage, shelter and to preserve the earth's surface. Today, underground use touches our lives in many ways--providing space and protection for many essential services ,.~uch as water, waste, power, and transport--but it is invisible. This invisibility is one of its assets, but also makes it difficult to appreciate, visualize, and plat,; for. --NSF Colloquium Participants, July 1995 Introduction " n July 1995, a colloquium was held in Minnesota to examine the current and future trends for the utiliza- • tion of underground space. During the three-day colloquium, the basic framework for the colloquium report was developed and the key findings of the colloquium were reached. This report summarizes the highlights of the discussions conducted and the central findings of the colloquium, as well a,,~explanatory material not presented at the colloquium but reviewed by all colloquium partici- pants for consistency with the colloquium discussions. The colloquium brought together a diverse group of people---leaders in shaping our built environment--for a threefold purpose: 1. To assess the importance of underground space in future efforts to achieve sustainable human development. 2. To identify impediments to achieving the greatest value of underground space as an element of our built environment. 3. To identify opportunities for government policy, re- search and technology, and other initiatives to enhance our abilities to develop and use underground space. This report was prepared by Dr. Raymond Sterling, who chaired the Colloquium on Underground Space Utilization. It is reprinted herein with slight chanff~s,with permission ofthe author and ofthe National Science Foundation. Present address: Dr. Raymond Sterling, CETF Professor of Civil Engineering, Louisiana Teeh University, P.O. Box 1038, Ruston, LA 71272-0046, U.S.A. This general review and evaluation of the role of under- ground facilities in our future is essential to consideration of more specific actions to improve the cost-effectiveness or wider implementation of underground solutions. If under- ground space utilization is expected to diminish in relative importance in the future, or if it is felt to be a mature technology with little prospect for further efficiency en- hancements, then there is considerably less need or value for programs to address the opportunities that under- ground construction affords or the problems that it pre- sents. If, however, a broad group of experts covering all the facets of our built environment were to agree that under- ground space utilization was increasing in relative impor- tance (and would continue to increase), this consensus would form a more secure underpinning for assumptions that are often made in this regard by people active in the field of underground space use. Further, it would highlight the need to rapidly develop improved technologies and administrative procedures to allow more effective future use of underground space. As the title of the report suggests, this colloquium was partially an attempt to revisit and update similar discus- sions held in the early 1970s. These discussions led to both national and international undertakings with respect to underground space utilization. Nationally, the Under- ground Construction Research Council (now the Under- ground Technology Research Council) developed a report entitled "The Use of Underground Space to Achieve Na- tional Goals" (UCRC 1972). The report recommended an investment of $US100 million to $US1 billion annually for 5 to 10 years in research and development to allow major improvements in underground technologies and a major transfer of appropriate infrastructure facilities to the un- derground. It was estimated that such a transfer would result in $6 billion in annual economic savings to the U.S. Interest in this topic in the U.S. and in a number of other countries was spurred by an advisory conference on tunnel- ing organized by the Organization for Economic Coopera- tion and Development (OECD) in June 1970. Several activities resulted from these beginnings. In the U.S., the Interagency Committee on Excavation Technology, the U.S. National Committee on Tunneling Technology, and the American Underground-Space Association (now the Ameri- Tunnelling and Underground Space Technology, Vol. 11,No.3, pp. 263-270, 1996 Copyright ©1996 Elsevier Science Ltd Printedin Great Britain.Allrights reserved 0886-7798/96 $15.00 + 0.00 Pergamon