Geotechnology: Its Impact on Economic Growth, the Environment, and National Security (1989)

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REFERENCE COPY FOR LIBRARY USE ONLY GEOTECHNOLOGY ~ Its Impact on Economic Growth, the Environment, and National Security The Geotechnical Board Commission on Engineering and Technical Systems National Research Council PROPERTY OF NRC LIBRARY FEB 2 5 1989 NATIONAL ACADEMY PRESS Washington, D.C. 1989

TA 105.4 W37 189 C. | NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Insti- tute of Medicine. The members of the board responsible for this report were chosen for their special expertise and with regard for appropriate balance between government, industry, and academia. This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1868, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Frank Press is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organisation of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognises the superior achievements of engineers. Dr. Robert M. White is president of the National Academy of Engineering. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of the appropriate professions in the estimation of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Samuel O. Thier is president of the Institute of Medicine. The National Council was organised by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy’s purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Frank Press and Dr. Robert M. White are chairman and vice chairman, respectively, of the National Research Council. This project was sponsored by the National Research Council (NRC) Fund. The NRC Fund is a pool of private, discretionary, nonfederal funds that is used to support a program of Academy-initiated studies of national issues in which science and technology figure significantly. The NRC Fund consists of contributions from a consortium of private foundations including the Carnegie Corporation of New York, the Charles E. Culpeper Foundation, the William and Flora Hewlett Foundation, the John D. and Catherine T. MacArthur Foundation, the Andrew W. Mellon Foundation, the Rockefeller Foundation, and the Alfred P. Sloan Foundation; the Academy Industry Program, which seeks annual contributions from companies that are concerned with the health of U.S. science and technology and with public policy issues with technology content; and the National Academy of Sciences and the National Academy of Engineering endowments. Copies are available from: The Geotechnical Board National Research Council 2101 Constitution Avenue, N.W. Washington, D.C. 20418

THE GEOTECHNICAL BOARD Board Members THOMAS R. KUESEL (Chairman), Parsons Brinckerhoff Quade & Douglas, Inc., New York, New York JAMES M. DUNCAN, Virginia Polytechnic Institute and State University, Blacksburg, Virginia COLIN A. HEATH, NUS Corporation, Gaithersburg, Maryland FRANCOIS E. HEUZE, Lawrence Livermore National Laboratory, Livermore, California JAMES K. MITCHELL, University of California, Berkeley, California JOHN RAMAGE, CH2M Hill, Milwaukee, Wisconsin KENNETH H. STOKOE, II, University of Texas, Austin, Texas PAUL Y. THOMPSON, University of Florida, Gainesville, Florida EUGENE B. WAGGONER, Engineering Geologist, Vallejo, California Liai DOUGLAS D. BOLSTAD, Chairman, U.S. National Committee for Rock Mechanics NORMAN H. BROOKS, Commission on Engineering and Technical Systems THOMAS D. O’ROURKE, Chairman, U.S. National Comittee on Tunneling Technology STAVROS PAPADAPOULOS, Water Science and Technology Board DWIGHT A. SANGREY, Member, Committee on Ground Failure Hazards RONALD E. SMITH, Association of Soils and Foundation Engineers RICHARD D. WOODS, American Society of Civil Engineers 1ii

Staff RILEY M. CHUNG, Director LYNNE F. CRAMER, Board Coordinator VIRGINIA M. LYMAN, Staff Associate DANA G. CAINES, Administrative Assistant iv

PREFACE In June 1987, the Governing Board of the National Research Council approved the establishment of the Geotechnical Board. Formed to provide the National Research Council with a unified capability to address geotechnical engineering and science issues of nation- al scope, the Board consists of nine members drawn from govermment, industry, and academia. To ensure a stream of invigorating ideas, the members were chosen to represent a broad spectrum of backgrounds and exper- tise. To initiate its activities the Board undertook the preparation of this report. It is aimed at the agen- cies and organizations that will use geotechnical en- gineering and science to address certain key issues facing the nation. The report identifies the present and future concerns of the geotechnical community and the potential of this commmity to help address nation- al and global issues and problems. This report dis- cusses research opportunities; notes the strengths and problems of private industry; offers insights on so- cial and political situations that have affected the technical progress of the discipline; delineates the interests of federal, state, and local governments ; and suggests opportunities for coordinated activities with other disciplines. Finally, the Board presents an action agenda for selected national issues in which it notes those areas in which geotechnology can play an important’ role and suggests how this role can be accomplished. Discus- sion of these and related issues with the Boar is invited. The Board serves the technical conmmnity and government agencies by facilitating the application of geotechnical expertise to national problems. As a

board of the National Research Council, operating un- Ger the auspices of the National Academy of Sciences and the National Academy of Engineering, it is charged with advising the federal agencies, on request, in the technical areas of its expertise. The Board is able to mobilize ad hoc panels to address specific issues or problems, and provides overview and direction to such special panels. The management of these panels is guided by some strict procedures of the National Re— search Council aimed at ensuring an unbiased and appro— priate assessment of the specific issue. Appendix in- cludes a discussion that delineates the National Re— search Council process. Vi

CONTENTS 1 THE SCOPE OF GEOTECHNOLOGY........ cocccceee cocceel Areas of Application, 8 Methods Used in Geotechnology, 17 2 THE ROLE OF GEOTECHNOLOGY IN NATIONAL ISSUES....22 Waste Management, 23 Infrastructure Development and Rehabilitaiton, 31 Construction Efficiency and Innovation, 37 National Security, 45 Resource Discovery and Recovery, 50 Mitigation of Natural Hazards, 58 Frontier Exploration and Development, 64 3 CROSS-CUTITING ISSUES... ccc ccccee ec cccccccccccee 67 Geotechnical Education, 67 Professional Practice, 67 Research and Technology Transfer, 70 4 ACTION AGENDA... ..ccccccccccccccccccce eccccccceel lL Waste Management, 71 Infrastructure and Rehabilitation, 73 Construction Efficiency and Innovation, 74 National Security, 76 Resource Discovery and Recovery, 76 Mitigation of Natural Hazards, 77 Frontier Exploration and Development, 79 Cross-Cutting Issues, 79 Vii

EXECUTIVE SUMMARY Every work of man is built on, in, or with the earth, except those things that fly, float, or fall down, and these last three mst start or end with som earth contact. Many of man’s greatest structural achievements have been built with soil and rock materials, and this trend is likely to contime. The science and engineering of soil and rock and of the water and other fluids that permeate them are critical for addressing a wide range of national issues. The earth’s subsurface has many present or potential natural and man-made uses, and knowledge of the science and technology of geotechnology is necessary to protect and exploit this resource. To orient the lay reader, this report opens with a discussion of the scope of geotechnology-—-its areas of application and its methods. This discussion is fol- lowed by a review of the present and potential role of geotechnology in a number of national issues. The con- clusion indicates how the National Research Council, through the Geotechnical Board, can assist in olving the technical problems that arise out of these na- tional issues by providing technical expertise to govermment agencies for policymaking purposes am by serving as a stimulus to the geotechnical community for research and technology transfer as they relate to these issues. Geotechnology is the term used in this report to signify a broad range of disciplines that contribute to the understanding and engineeri g of soil and rock materials and is defined as a field of professional practice and research that draws heavily on the ele- ments of rock and soil mechanics and engineering geology. Other disciplines that contribute to geo- technology include civil engineering, mechanical engi- neering, geology, geohydrology, mining engineering, geophysics, seismology, petroleum engineering, and geochemistry. The disciplines are involved with the study, design, and construction of such things as 1

foundations for structures, mines, tunnels, retaining structures, cut slopes, dams, subgrades, boreholes and wells. The application of geotechnology typically com- prises four phases--site characterization, design, construction, and performance assessment. The first phase includes both field exploration and laboratory testing. Design involves the interpretation and evalu- ation of site data and the development and application of theories of ground mass behavior, ground-structure interaction, and groundwater flow. Construction geo- technology consists of adjusting the design and con- struction methods to accommodate actual ground con- ditions. Performance assessment is needed to account for the great variability of the natural ground. Validation of the design by measurement and evaluation of field performance of structures with geotechnical camponents during construction and in operation is fre- quently required. Seven categories of national issues have been iden- tified in which the development and application of geo- technology can have significant national impacts. These seven categories are described below. 1. Waste Management. The cleanup and management of solid, hazardous, and radioactive wastes is a major national issue whose resolution depends heavily on geotechnology. Waste management issues are highly visible and volatile in most public domains. Public interest underscores both the importance and diffi- culty of this effort. The hazardous waste problem involves a camplex and Changing regulatory structure, difficult liability con- siderations, an adversarial environment, and unclear standards of practice. Research and development are needed to establish authoritative and reasonable tech- nical standards, which are required if the problem is to be moved from emotional debate to rational treat- ment. The long-term storage of radioactive wastes in deep geological repositories is an even more emotional issue that poses special geotechnical challenges. Research is needed to develop a better understanding of the flow of groundwater through rock and the ef- fects of heat on rock masses to provide assurance that radionuclides are not transported over thousands of 2

years or, if so, that they do not adversely affect public health. Compliance with licensing regulations requires the development of evaluation amd analysis methods that can provide reliable assurance of long- term containment, yet that recognize the inherent un- certainties associated with the underground environment. 2. Infrastructure Development and Rehabilitation. The underground enviromment is presently used to house water distribution networks, wastewater collection systems, and solid waste disposal sites. Oil, gas, electricity, and telecommunications also use the underground environment, while transportation systems are founded on or built within the subsurface. The lack of surface space, historic preservation concerns, economic preservation issues, and other new demands will require increased utilization of the un- Gerground environment to improve and expand our infra- structure systems. Potential uses, which are, no doubt, not now envisioned, are also on the horizon, for example, underground networks for solid waste re- cycling, vast underground resource storage facilities, and underground transportation corridors. Areas deserving special consideration include the following: e Construction influences on existing adjacent structures. Improved methods of predicting. construction effects and protecting existing facilities are rapidly emerging. @e Trenchless construction for the installation and renovation of utility pipe networks. @ Development and application of new materials. The use of plastic pipe, polymers, and geosynthetic materials should be exploited more fully in addressing the needs of infrastructure systems. @ Maintenance and renewal of aging infrastructure systems. Advances in remote sensing systems to locate and assess the quality of infrastructure sys ems are required. @e Introduction of an interdisciplinary approach to solving the diverse needs of complex infrastructure systems.

3. Construction Efficiency and Innovation. The reputation of the U.S. construction industry as a world leader has withered in the face of foreign com petition. To a significant extent, the loss of stand- ing is the result of artificial institutional con- straints. Traditional contracting methods frequently emphasize low-cost design, which often results in expensive construction, operation, and maintenance. Such attitudes foster overconservatism and discourage innovation. The growth of liability issues has served as a disincentive to the adoption of new methods and techniques. Short-term project funding has stunted long-term research. The U.S. construction industry invests much less in research amd development tha do almost all of its foreign counterparts. The education of legislative and govermment agency leaders is required to develop an awareness of how cur- rent U.S. administrative and social policies are stul- tifying both design and construction amd reducing the competitiveness of the U.S. construction industry. A long-range policy needs to be developed to foster tech- nical education, research, and technology transfer from laboratories to areas in which they can be actual- ly implemented. Geotechnical scientists and engineers are aware of much existing technology that could be ap- plied to improve construction efficiency and productiv-— ity, if the restraints of institutional policies were relaxed. 4. National Security. Input from geotechnical scientists and engineers is required to assess the vulnerability and survivability of defense instal- lations from nuclear and high-explosive weapons. There are defense implications in being able to assess the underground technological capabilities of foreign countries, and input from geotechnical scientists and engineers in providing this assessment is needed. The ability to construct military facilities under readi- ness and postattack situations is a defense question, as is our ability to verify muclear test treaties. Assessment of these matters is at the forefront of ex- isting technology and experience in underground con struction and mechanics, and major research programs are needed to develop satisfactory solutions.

5. Resource Discovery and Recovery. The development and conservation of natural resources, independent of foreign sources, is vital to economic and political strength and to national security. Geotechnology is involved in developing methods to extract low-grade ores and diffuse mineral resources and in safely returning waste products to the earth. Energy resources include oil am gas, coal, m- clear energy, hydropower, geothermal energy, under- ground pumped hydropower, and compressed air. Enhancement of the practical recoverability of aifficult-to-get energy reserves and development of technologies to exploit them require sophisticated geotechnical expertise. Deep mining and extraction of nonfuel minerals from low-grade ore require a new theo- retical understanding of the behavior of the natural enviroment and the practical development of tools to work effectively in that environment. Water resource development and control of both surface water an groundwater flow make heavy use of geotechnology. Progress in these areas requires expanded research and development of practical techniques and equipment. New demands necessitate an increasingly sophisticated geotechnical capability. Conversely, existing tech- nologies have not been fully or creatively utilized. 6. Mitigation of Natural Hazards. Natural haz- ards include catastrophic phenomena such as earth- quakes, landslides, floods, and volcanoes, as well as long-term hazards such as subsidence, swelling soils, and slope failures. Many of the most severe hazards involve movement of earth and water, for example, land- slides, volcanic eruptions, earthquakes, swelling soils, and subsidence. Geotechnical solutions are used in mitigation strategies for other hazards, for example, flood control canals and embankments, shore- line erosion control for hurricanes, and underground shelters for tornadoes. Hazard mitigation involves federal, state and local government programs, as well as programs of private industry. It is also the focus of the up- coming International Decade for Natural Disaster Reduction, which is being developed through the United Nations in response to an initiative of the National Research Council.

7. Frontier Exploration and Development. The polar regions, the deep oceans, the deep underground, and extraterrestrial space are the remaining natural frontiers. Their exploration and development will require satisfactory solution of geotechnical problems that are beyond the range of present experience. ing the behavior of arctic soils and perma- frost, deep subsea soils, and lunar am planetary materials will require extensive research on arn development of the frontiers of geotechnology. This report introduces the opportunities offered by geotechnology for addressing the evolving problems that face the nation. It is also intended that the report introduce the capabilities of the Geotechnical Board as an instrument of the National Research Council.

THE SCOPE OF GEOTECHNOLOGY Geotechnology is the term used in this report to Gescribe both the science and engineering of soil de- posits, rock masses, and the fluids they contain-—- referred to hereafter as earth materials. It has many facets and draws upon a variety of disciplines that work with earth materials. The application of geo- technology allows us to improve our environment, miti- gate natural hazards, and construct engineered facili- ties to improve our quality of life. All structures that man contemplates rely in same way on earth materials for their success. Dams are usually constructed from, and always founded on, earth materials. Canals, locks, and other waterways must utilize walls that hold back earth materials. Buildings are founded on earth materials and must interact properly with these materials when they are subject to shock waves emanating from the ground (earthquakes, for example). Tunnels for highways, railroads, subways, sewer and water conveyances, de- fense purposes, and utility services are constructed within the ground. Resources such as coal, oil, gas, and minerals are extracted from the ground. Barriers and filters are made of earth materials to isolate toxic and hazardous products from the community. Earth materials are abundant and available at low cost and will play increasingly important roles in construc- tion. Nearly every geotechnical problem involves con- siderations of fluid flow. The strength, deformation, and stability of soil and rock masses are dependent on the distribution, pressure, and properties of the fluids within the rock masses. Geohydrology is the science of the movement of groundwater and of the phys- ical and chemical interactions of fluids and geologic materials. Geohydrology has also come to include the study of underground water resources. Water resource distribution, development, maintenance, protection, and remediation are important facets of this field, as 7

are conservation, recharge, and avoidance of subsi- dence resulting from aquifer overdraft. Geotechnical solutions to the problems involved with the use of water resources effectively and wisely have recently become an important part of geotechnology. A mumber of disciplines are included under the purview of geotechnology, as depicted in Figure 1. Geologists study the makeup and character of earth materials with interests ranging from macroscopic subjects such as tectonics amd continental drift theories to microscopic subjects such as crystal- lography and microfracturing. Geotechnical engineers study the behavior of earth materials under static and dynamic loads that are applied when structures are con- structed within or upon earth materials and use this knowledge of behavior to design retaining walls, foun- dations, underground powerhouses, highway roadcuts, tunnels, and roadway subgrades. Special engineering considerations arise for geotechnical engineers in con- structing barriers to isolate hazardous wastes, under- ground repositories to dispose of radioactive wastes, and hardened structures to house defense installa- tions. Hydrologists explain the flow of fluids through earth materials, and mining engineers help to optimize the extraction of earth materials for re- source utilization. Geophysicists, camputer scien- tists, mechanical engineers, materials scientists, seismologists, geochemists, and structural engineers, to name a few, also contribute to the field of geotechnology. The scope of geotechnology is delineated below, and the breadth and nature of this discipline are Gefined and characterized by describing the areas of application and methods used in geotechnology. AREAS OF APPLICATION Geotechnology plays a significant role in the following areas of application. "Foundation engineering is the art of selecting, designing, and constructing the elements that transfer 8

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the weight of a structure to the underlying soil or rock." These elements might consist of footings, slabs, deep foundations in various types and configura- tions, and combinations of the three. Foundation engi- neering uses the data from site exploration, in situ testing, and laboratory testing, combined with theo- ries of the physical and mechanical behavior of soils and rocks, to develop estimates of the probable be- havior of foundations when they are in service. Owing to the highly complex nature of the distribution and behavior of the soils and rocks that form the crust of the earth, the successful practice of foundation engi- neering requires considerable experience and judgment, and is an art as well as a science. Mining Engi . Mining engineering incorporates most of the geo- technical disciplines necessary to design and operate an open pit, an underground excavation, and associated waste disposal facilities. Development and extraction of the materials to realize the maximum economic poten- tial of a mine often create loads that generate large Geformations in the surrounding rock and soil. One of the primary concerns is the control of soil and rock displacements in the pit slope, in the mine, or at the disposal site. An understanding of geomechanics and the interaction between geotechnical materials and sup- port systems is critical and requires an analytical capability of predicting material mass behavior under complex geologic conditions. The control of water for improving the strength of soil and rock masses and restricting the development and movement of heavy metal and acid contamination is also becoming an increasingly important geotechnical aspect of mining. beck, Ralph B., et al. 1974. Foundation Engineer- ing (Forward to 1st ed.). New York: John Wiley. 10

Tunneling Technology The engineered design of underground openings, in- cluding tunnels, involves the application of geome- chanical principles. Tunneling technology is needed for subways, highways, railroads, water and sewer con- veyances, underground powerplants, and underground military facilities. Inherent in the development of a Gesign methodology for constructing underground open- ings is attention to all details that will enhance the ability of rock or soil masses to becom self- supporting and to avoid excessive deformation of the surrounding ground. Thus, tunnel engineering involves the design of a support system to develop a stable re- sponse to any addition or changes in the loads that are present. A consensus is developing that such a de- Sign must be flexible enough to adapt to the ever pre- sent possibility of the presence of significant dif- ferences between expected conditions and the situation that is actually encountered in the ground. Geotechnology must interact heavily with the construction aspects of tunneling technology. The amount of support required to maintain an opening Gepends on the material changes induced by excavation methods, the time delay between excavation and the installation of support, and the type of support in- stalled. The design and construction of any final lin- ing for an underground opening is also part of tunnel- ing technology. The high cost of tunneling places an emphasis on the ability of geotechnology to predict the ground con- ditions ahead of the tunneling operation. An example of the result of encountering an unexpected condition on a recent project is outlined in the box below. Site characterization is thus intimately tied to the success of tunneling projects. UNEXPECTED ROCK CONDITIONS INCREASE TUNNEL PROJECT COSTS During the construction of a 28,000-foot tunnel for the Milwaukee Metropolitan Sewerage District, work- ers encountered unstable limestone. The unanticipated ‘rock and water conditions set the job back 5 months 11

and increased the cost of the project by $45 million. The 32-foot-diameter tunnel project was begun in 1986 under a $46 million contract. The contractor hit un- stable conditions and large (3,000 gallons per minute) water inflows approximately 7,000 feet into the job. Support was originally planned to consist of rockbolts and shotcrete as necessary, but steel ribs and timber lagging were installed in the areas of unstable rock. Additional water control measures, surface grouting, and lining requirements have also been implemented. it. dis anticipated that as much as 10,000 feet of tunnel may require these extraordinary measures. SS Slope Stability and Landslide Remediation Slope stability is of key importance for the con- struction of earth dams, transportation embankments, and engineered fills. Slope stability also plays a critical role in risk assessment and in establishing protective measures for natural areas. In the United States landslides cause at least $1 billion to $2 billion in economic losses and 25 to 50 deaths each year. The loss of life from landslides is comparable to the total loss of life from floods, earthquakes, and hurricanes combined. Landslide engineering involves the identification of potential slides, site exploration, monitoring of movements, and a variety of different stabilization techniques ranging from groundwater control to soil and rock reinforcement. Relationships between land- slides and weather patterns are being investigated, and real-time landslide warning systems have been im- 2committee on Ground Failure Hazards, National Re- search Council. 1985. Reducing Losses from Landslid- ing in the United States. Washington, D.C.: National Academy Press. 3krohn, J.P., amd J.E. Slosson. 1976. Landslide Potential in the United States. California Geology 29 (10) :224-231. 12

plemented for commumities along the Pacific Coast. Real-time warning systems combine weather forecasts of the duration and intensity of rainfall, estimates ofrunoff, and slope stability analyses to identify potential landslides and debris flows. Earth Retaining Structures Some of the most rapid and pervasive changes in geotechnical engineering are occurring in the area of earth retaining structures. Over the past decade, methods of support have been expanded from conven- tional walls with external bracing to the inclusion of reinforcing elements installed within soil and rock for enhanced tensile and shear capacity. The design of earth retention systems is based on the properties of strength and deformability of earth materials and models of their behavior when they are umder loads. Retaining structures are used extensively for highway and railroad stabilization, as waterfront structures, as support systems for basements and underground trans- portation facilities, and for temporary reinforcement during the construction of water conveyance structures and other public utilities. New systems of internal support involve polymeric materials for tensile strip and grid reinforcement, as well as filter materials for proper drainage and water pressure control. Technologies are evolving for in situ reinforcement which involve jet grouting, soil- crete columns, slurry trench techniques, and the injec- tion of cement, silica, or resin-based grouts under pressure. : Earthquake seismology and engineering includes locating and mapping faults, estimating the prob- ability of their movement, and estimating the probable intensity of the forces resulting from their movement. Understanding and predicting the behavior of geotech- nical materials and soil-structure interactions during earthquake loading encompass a variety of topics. The response of rock and soil to dynamic loads mst be un- 13