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NATIONAL
NCHRP REPORT 556
COOPERATIVE
HIGHWAY
RESEARCH
PROGRAM
Design and Construction
Guidelines for Geosynthetic-
Reinforced Soil Bridge
Abutments with a Flexible Facing
OCR for page R2
TRANSPORTATION RESEARCH BOARD EXECUTIVE COMMITTEE 2006 (Membership as of November 2005)
OFFICERS
Chair: John R. Njord, Executive Director, Utah DOT
Vice Chair: Michael D. Meyer, Professor, School of Civil and Environmental Engineering, Georgia Institute of Technology
Executive Director: Robert E. Skinner, Jr., Transportation Research Board
MEMBERS
MICHAEL W. BEHRENS, Executive Director, Texas DOT
ALLEN D. BIEHLER, Secretary, Pennsylvania DOT
LARRY L. BROWN, SR., Executive Director, Mississippi DOT
DEBORAH H. BUTLER, Vice President, Customer Service, Norfolk Southern Corporation and Subsidiaries, Atlanta, GA
ANNE P. CANBY, President, Surface Transportation Policy Project, Washington, DC
JOHN L. CRAIG, Director, Nebraska Department of Roads
DOUGLAS G. DUNCAN, President and CEO, FedEx Freight, Memphis, TN
NICHOLAS J. GARBER, Professor of Civil Engineering, University of Virginia
ANGELA GITTENS, Vice President, Airport Business Services, HNTB Corporation, Miami, FL
GENEVIEVE GIULIANO, Director, Metrans Transportation Center, and Professor, School of Policy, Planning, and Development,
USC, Los Angeles
BERNARD S. GROSECLOSE, JR., President and CEO, South Carolina State Ports Authority
SUSAN HANSON, Landry University Professor of Geography, Graduate School of Geography, Clark University
JAMES R. HERTWIG, President, CSX Intermodal, Jacksonville, FL
GLORIA JEAN JEFF, Director, Michigan DOT
ADIB K. KANAFANI, Cahill Professor of Civil Engineering, University of California, Berkeley
HERBERT S. LEVINSON, Principal, Herbert S. Levinson Transportation Consultant, New Haven, CT
SUE MCNEIL, Professor, Department of Civil and Environmental Engineering, University of Delaware
MICHAEL R. MORRIS, Director of Transportation, North Central Texas Council of Governments
CAROL A. MURRAY, Commissioner, New Hampshire DOT
MICHAEL S. TOWNES, President and CEO, Hampton Roads Transit, Hampton, VA
C. MICHAEL WALTON, Ernest H. Cockrell Centennial Chair in Engineering, University of Texas, Austin
LINDA S. WATSON, Executive Director, LYNX--Central Florida Regional Transportation Authority
MARION C. BLAKEY, Federal Aviation Administrator, U.S.DOT (ex officio)
JOSEPH H. BOARDMAN, Federal Railroad Administrator, U.S.DOT (ex officio)
REBECCA M. BREWSTER, President and COO, American Transportation Research Institute, Smyrna, GA (ex officio)
GEORGE BUGLIARELLO, Chancellor, Polytechnic University, and Foreign Secretary, National Academy of Engineering (ex officio)
J. RICHARD CAPKA, Acting Administrator, Federal Highway Administration, U.S.DOT (ex officio)
THOMAS H. COLLINS (Adm., U.S. Coast Guard), Commandant, U.S. Coast Guard (ex officio)
JAMES J. EBERHARDT, Chief Scientist, Office of FreedomCAR and Vehicle Technologies, U.S. Department of Energy (ex officio)
JACQUELINE GLASSMAN, Deputy Administrator, National Highway Traffic Safety Administration, U.S.DOT (ex officio)
EDWARD R. HAMBERGER, President and CEO, Association of American Railroads (ex officio)
DAVID B. HORNER, Acting Deputy Administrator, Federal Transit Administration, U.S.DOT (ex officio)
JOHN C. HORSLEY, Executive Director, American Association of State Highway and Transportation Officials (ex officio)
JOHN E. JAMIAN, Acting Administrator, Maritime Administration, U.S.DOT (ex officio)
EDWARD JOHNSON, Director, Applied Science Directorate, National Aeronautics and Space Administration (ex officio)
ASHOK G. KAVEESHWAR, Research and Innovative Technology Administrator, U.S.DOT (ex officio)
BRIGHAM MCCOWN, Deputy Administrator, Pipeline and Hazardous Materials Safety Administration, U.S.DOT (ex officio)
WILLIAM W. MILLAR, President, American Public Transportation Association (ex officio)
SUZANNE RUDZINSKI, Director, Transportation and Regional Programs, U.S. Environmental Protection Agency (ex officio)
ANNETTE M. SANDBERG, Federal Motor Carrier Safety Administrator, U.S.DOT (ex officio)
JEFFREY N. SHANE, Under Secretary for Policy, U.S.DOT (ex officio)
CARL A. STROCK (Maj. Gen., U.S. Army), Chief of Engineers and Commanding General, U.S. Army Corps of Engineers (ex officio)
NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM
Transportation Research Board Executive Committee Subcommittee for NCHRP
JOHN R. NJORD, Utah DOT (Chair) MICHAEL D. MEYER, Georgia Institute of Technology
J. RICHARD CAPKA, Federal Highway Administration ROBERT E. SKINNER, JR., Transportation Research Board
JOHN C. HORSLEY, American Association of State Highway MICHAEL S. TOWNES, Hampton Roads Transit, Hampton, VA
and Transportation Officials C. MICHAEL WALTON, University of Texas, Austin
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NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM
NCHRP REPORT 556
Design and Construction Guidelines
for Geosynthetic-Reinforced Soil Bridge
Abutments with a Flexible Facing
JONATHAN T. H. WU
KEVIN Z. Z. LEE
SAM B. HELWANY
KANOP KETCHART
University of Colorado at Denver
Denver, CO
S UBJECT A REAS
Highway and Facility Design · Bridges, Other Structures, and Hydraulics and Hydrology · Soils, Geology, and Foundations
Research Sponsored by the American Association of State Highway and Transportation Officials
in Cooperation with the Federal Highway Administration
TRANSPORTATION RESEARCH BOARD
WASHINGTON, D.C.
2006
www.TRB.org
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NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM NCHRP REPORT 556
Systematic, well-designed research provides the most effective Price $25.00
approach to the solution of many problems facing highway
Project 12-59
administrators and engineers. Often, highway problems are of local
ISSN 0077-5614
interest and can best be studied by highway departments
individually or in cooperation with their state universities and ISBN 0-309-09845-9
others. However, the accelerating growth of highway transportation Library of Congress Control Number 2006921471
develops increasingly complex problems of wide interest to © 2006 Transportation Research Board
highway authorities. These problems are best studied through a
coordinated program of cooperative research.
In recognition of these needs, the highway administrators of the
American Association of State Highway and Transportation COPYRIGHT PERMISSION
Officials initiated in 1962 an objective national highway research Authors herein are responsible for the authenticity of their materials and for obtaining
program employing modern scientific techniques. This program is written permissions from publishers or persons who own the copyright to any
previously published or copyrighted material used herein.
supported on a continuing basis by funds from participating
member states of the Association and it receives the full cooperation Cooperative Research Programs (CRP) grants permission to reproduce material in this
publication for classroom and not-for-profit purposes. Permission is given with the
and support of the Federal Highway Administration, United States
understanding that none of the material will be used to imply TRB, AASHTO, FAA,
Department of Transportation. FHWA, FMCSA, FTA, or Transit Development Corporation endorsement of a
The Transportation Research Board of the National Academies particular product, method, or practice. It is expected that those reproducing the
was requested by the Association to administer the research material in this document for educational and not-for-profit uses will give appropriate
program because of the Board's recognized objectivity and acknowledgment of the source of any reprinted or reproduced material. For other uses
of the material, request permission from CRP.
understanding of modern research practices. The Board is uniquely
suited for this purpose as it maintains an extensive committee
structure from which authorities on any highway transportation
subject may be drawn; it possesses avenues of communications and NOTICE
cooperation with federal, state and local governmental agencies, The project that is the subject of this report was a part of the National Cooperative
universities, and industry; its relationship to the National Research Highway Research Program conducted by the Transportation Research Board with the
Council is an insurance of objectivity; it maintains a full-time approval of the Governing Board of the National Research Council. Such approval
research correlation staff of specialists in highway transportation reflects the Governing Board's judgment that the program concerned is of national
importance and appropriate with respect to both the purposes and resources of the
matters to bring the findings of research directly to those who are in National Research Council.
a position to use them.
The members of the technical committee selected to monitor this project and to review
The program is developed on the basis of research needs
this report were chosen for recognized scholarly competence and with due
identified by chief administrators of the highway and transportation consideration for the balance of disciplines appropriate to the project. The opinions and
departments and by committees of AASHTO. Each year, specific conclusions expressed or implied are those of the research agency that performed the
areas of research needs to be included in the program are proposed research, and, while they have been accepted as appropriate by the technical committee,
to the National Research Council and the Board by the American they are not necessarily those of the Transportation Research Board, the National
Research Council, the American Association of State Highway and Transportation
Association of State Highway and Transportation Officials. Officials, or the Federal Highway Administration, U.S. Department of Transportation.
Research projects to fulfill these needs are defined by the Board, and
Each report is reviewed and accepted for publication by the technical committee
qualified research agencies are selected from those that have
according to procedures established and monitored by the Transportation Research
submitted proposals. Administration and surveillance of research Board Executive Committee and the Governing Board of the National Research
contracts are the responsibilities of the National Research Council Council.
and the Transportation Research Board.
The needs for highway research are many, and the National
Cooperative Highway Research Program can make significant
contributions to the solution of highway transportation problems of
mutual concern to many responsible groups. The program,
however, is intended to complement rather than to substitute for or
duplicate other highway research programs.
Published reports of the
NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM
are available from:
Transportation Research Board
Business Office
NOTE: The Transportation Research Board of the National Academies, the 500 Fifth Street, NW
National Research Council, the Federal Highway Administration, the American Washington, DC 20001
Association of State Highway and Transportation Officials, and the individual and can be ordered through the Internet at:
states participating in the National Cooperative Highway Research Program do http://www.national-academies.org/trb/bookstore
not endorse products or manufacturers. Trade or manufacturers' names appear
herein solely because they are considered essential to the object of this report. Printed in the United States of America
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The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished schol-
ars engaged in scientific and engineering research, dedicated to the furtherance of science and technology
and to their use for the general welfare. On the authority of the charter granted to it by the Congress in
1863, the Academy has a mandate that requires it to advise the federal government on scientific and techni-
cal matters. Dr. Ralph J. Cicerone is president of the National Academy of Sciences.
The National Academy of Engineering was established in 1964, under the charter of the National Acad-
emy of Sciences, as a parallel organization 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
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ments of engineers. Dr. William A. Wulf is president of the National Academy of Engineering.
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and the National Academy of Engineering in providing services to the government, the public, and the
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respectively, of the National Research Council.
The Transportation Research Board is a division of the National Research Council, which serves the
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COOPERATIVE RESEARCH PROGRAMS STAFF FOR NCHRP REPORT 556
ROBERT J. REILLY, Director, Cooperative Research Programs
CRAWFORD F. JENCKS, Manager, NCHRP
TIMOTHY G. HESS, Senior Program Officer
EILEEN P. DELANEY, Director of Publications
HILARY FREER, Senior Editor
ELLEN CHAFEE, Assistant Editor
NCHRP PROJECT 12-59 PANEL
Field of Design--Area of Bridges
ROBERT K. BARRETT, Yenter Companies, Grand Junction, CO (Chair)
NASER ABU-HEJLEH, Colorado DOT
TIMOTHY ADAMS, South Carolina DOT
BRUCE E. BRUNETTE, Alaska DOT
JERRY A. DIMAGGIO, Federal Highway Administration
JAMES B. HIGBEE, Utah DOT
GORDON KELLER, USDA Forest Service
LAURA KRUSINSKI, Maine DOT
JAWDAT SIDDIQI, Ohio DOT
MICHAEL ADAMS, FHWA Liaison
G.P. JAYAPRAKASH, TRB Liaison
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This report presents the findings of research undertaken to develop a rational
FOREWORD design method and construction guidelines for using geosynthetic-reinforced soil
By Timothy G. Hess (GRS) systems in bridge abutments. This report will be of immediate interest to pro-
Staff Officer fessionals responsible for designing and constructing GRS structures.
Transportation Research
Board
The use of geosynthetic-reinforced soil (GRS) systems as the foundation for or as
integral structural components of bridge abutments and piers is receiving increased
attention and interest. The soil mass of GRS systems is reinforced in layers with a poly-
meric geosynthetic (e.g., geogrids or geotextiles), and the layered reinforcement is
attached to facing elements that constitute the outer wall. Because the facing elements
are commonly composed of articulated units that are not rigidly attached to each other,
the wall is deemed flexible. Various materials, including natural rock, concrete block,
gabion, or timber, may be used for the flexible facing. GRS structures are more forgiv-
ing to differential foundation settlement thus minimizing the bump that commonly
develops between the roadway and bridge. GRS structures are more adaptable to low-
quality backfill, easier to construct, and more economical than their conventional coun-
terparts. GRS structures can be put into service quickly, can be built by maintenance
personnel, and are especially well suited to projects constructed in areas that are diffi-
cult to access with heavy equipment. GRS structures are an economical alternative for
temporary structures, because of their easy demolition and the recyclable nature of their
components, and for emergency work, because of reduced lead time and lower equip-
ment requirements.
Full-scale tests conducted by the FHWA and by the Colorado DOT on GRS bridge
abutments and piers with segmental modular block facing have demonstrated excellent
performance characteristics and very high load-carrying capacity. Even with the sig-
nificant advantages of GRS systems, the use of GRS structures in routine highway
bridge construction has not been widely adopted. The primary obstacles to adoption of
GRS systems in bridge construction are threefold. The first obstacle is the lack of a
rational and reliable design method for such bridge-supporting structures. For exam-
ple, although the vertical spacing of the reinforcement has been found to affect the per-
formance of the structure, current design methods fail to reflect this important fact.
Also, field-measured strains are known to be drastically smaller than those predicted
by current design methods. Clearly, the current design methods are not sufficient. The
second obstacle is the lack of well-developed guidelines and specifications for con-
structing the structures. Such guidelines and specifications are critical to the success-
ful application of this technology. The third obstacle is the perception that polymeric
geosynthetics may not be strong enough to meet the high service loads expected dur-
ing the design life of large bridge structures.
Under NCHRP Project 12-59, "Design and Construction of Segmental Geosynthetic-
Reinforced Soil (GRS) Bridge Abutments for Bridge Support," the University of
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Colorado at Denver developed a rational design method and construction guidelines for
GRS bridge abutments and approaches with flexible facing elements. After an extensive
literature review, the researchers conducted full-scale experiments and a thorough ana-
lytical study. Based on the research results, a rational design method and construction
guidelines were developed and design examples illustrating the design computation pro-
cedure were conducted and documented.
NCHRP Report 556 consists of the project final report and two appendixes. A
third appendix, "Verification of DYNA3D/LS-DYNA" is not included in this
report, but is available as NCHRP Web-Only Document 81 and can be found at
http://www4.trb.org/trb/crp.nsf.
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CONTENTS 1 SUMMARY
8 CHAPTER 1 Introduction and Research Approach
Problem Statement, 8
Research Objective, 9
Research Approach, 10
11 CHAPTER 2 Findings
Findings from Literature Study, 11
The NCHRP Full-Scale Experiments, 25
Findings from the Analytical Study, 41
96 CHAPTER 3 Interpretation, Appraisal, and Applications
Assessment of the NCHRP Test Abutments, 96
Limitations of the Design and Construction Guidelines, 98
Recommended Design Method, 98
Recommended Construction Guidelines, 111
Design Examples, 115
129 CHAPTER 4 Conclusions and Suggested Research
Conclusions, 129
Suggested Research, 130
131 REFERENCES
A-1 APPENDIX A Review of Construction Guidelines for GRS Walls
B-1 APPENDIX B A Brief Description of DYNA3D and LS-DYNA
C-1 APPENDIX C Verification of DYNA3D/LS-DYNASee NCHRP Web-Only
Document 81
