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Geosynthetic Reinforced Soil for Low-Volume Bridge Abutments

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Geosynthetic Reinforced Soil for Low-Volume Bridge Abutments EERC Publication ERXX-XX Geosynthetic Reinforced Soil for Low-Volume Bridge Abutments JANUARY 2012 Final Report Sponsored by Iowa Highway Research Board (IHRB Project TR-621) Iowa Department of Transportation (InTrans Project 10-380) About the Center for Earthworks Engineering Research The mission of the Center for Earthworks Engineering Research (CEER) at Iowa State University is to be the nation’s premier institution for developing fundamental knowledge of earth mechanics, and creating innovative technologies, sensors, and systems to enable rapid, high quality, environmentally friendly, and economical construction of roadways, aviation runways, railroad embankments, dams, structural foundations, fortifications constructed from earth materials, and related geotechnical applications. About the Bridge Engineering Center The mission of the Bridge Engineering Center (BEC) is to conduct research on bridge technologies to help bridge designers/owners design, build, and maintain long-lasting bridges. Disclaimer Notice The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the information presented herein. The opinions, findings and conclusions expressed in this publication are those of the authors and not necessarily those of the sponsors. The sponsors assume no liability for the contents or use of the information contained in this document. This report does not constitute a standard, specification, or regulation. The sponsors do not endorse products or manufacturers. Trademarks or manufacturers’ names appear in this report only because they are considered essential to the objective of the document. Non-Discrimination Statement Iowa State University does not discriminate on the basis of race, color, age, religion, national origin, sexual orientation, gender identity, genetic information, sex, marital status, disability, or status as a U.S. veteran. Inquiries can be directed to the Director of Equal Opportunity and Compliance, 3280 Beardshear Hall, (515) 294-7612. Iowa Department of Transportation Statements Federal and state laws prohibit employment and/or public accommodation discrimination on the basis of age, color, creed, disability, gender identity, national origin, pregnancy, race, religion, sex, sexual orientation or veteran’s status. If you believe you have been discriminated against, please contact the Iowa Civil Rights Commission at 800-457-4416 or Iowa Department of Transportation’s affirmative action officer. If you need accommodations because of a disability to access the Iowa Department of Transportation’s services, contact the agency’s affirmative action officer at 800-262-0003. The preparation of this (report, document, etc.) was financed in part through funds provided by the Iowa Department of Transportation through its “Agreement for the Management of Research Conducted by Iowa State University for the Iowa Department of Transportation,” and its amendments. The opinions, findings, and conclusions expressed in this publication are those of the authors and not necessarily those of the Iowa Department of Transportation. Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. IHRB Project TR-621 4. Title and Subtitle 5. Report Date Geosynthetic Reinforced Soil for Low-Volume Bridge Abutments January 2012 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. Pavana Vennapusa, David White, Wayne Klaiber, Shiyun Wang InTrans Project 10-380 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) Center for Earthworks Engineering Research and Bridge Engineering Center Iowa State University 11. Contract or Grant No. 2711 South Loop Drive, Suite 4600 Ames, IA 50010-8664 12. Sponsoring Organization Name and Address 13. Type of Report and Period Covered Iowa Highway Research Board Final Report Iowa Department of Transportation 14. Sponsoring Agency Code 800 Lincoln Way Ames, IA 50010 15. Supplementary Notes Visit www.ceer.iastate.edu for color PDFs of this and other research reports. 16. Abstract This report presents a review of literature on geosynthetic reinforced soil (GRS) bridge abutments, and test results and analysis from two field demonstration projects (Bridge 1 and Bridge 2) conducted in Buchanan County, Iowa, to evaluate the feasibility and cost effectiveness of the use of GRS bridge abutments on low-volume roads (LVRs). The two projects included GRS abutment substructures and railroad flat car (RRFC) bridge superstructures. The construction costs varied from $43k to $49k, which was about 50 to 60% lower than the expected costs for building a conventional bridge. Settlement monitoring at both bridges indicated maximum settlements ≤1 in. and differential settlements ≤ 0.2 in transversely at each abutment, during the monitoring phase. Laboratory testing on GRS fill material, field testing, and in ground instrumentation, abutment settlement monitoring, and bridge live load (LL) testing were conducted on Bridge 2. Laboratory test results indicated that shear strength parameters and permanent deformation behavior of granular fill material improved when reinforced with geosynthetic, due to lateral restraint effect at the soil- geosynthetic interface. Bridge LL testing under static loads indicated maximum deflections close to 0.9 in and non-uniform deflections transversely across the bridge due to poor load transfer between RRFCs. The ratio of horizontal to vertical stresses in the GRS fill was low (< 0.25), indicating low lateral stress on the soil surrounding GRS fill material. Bearing capacity analysis at Bridge 2 indicated lower than recommended factor of safety (FS) values due to low ultimate reinforcement strength of the geosynthetic material used in this study and a relatively weak underlying foundation layer. Global stability analysis of the GRS abutment structure revealed a lower FS than recommended against sliding failure along the interface of the GRS fill material and the underlying weak foundation layer. Design and construction recommendations to help improve the stability and performance of the GRS abutment structures on future projects, and recommendations for future research are provided in this report. 17. Key Words 18. Distribution Statement bridge abutments—bridge performance monitoring—geosynthetic reinforced No restrictions. soil—GRS—low-volume roads—railroad flat car bridges 19. Security Classification (of this 20. Security Classification (of this 21. No. of Pages 22. Price report) page) Unclassified. Unclassified. 134 NA GEOSYNTHETIC REINFORCED SOIL FOR LOW- VOLUME BRIDGE ABUTMENTS Final Report January 2012 Principal Investigator David J. White, Ph.D. Associate Professor and Director of CEER Co-Principal Investigators Pavana KR. Vennapusa, Ph.D. Research Assistant Professor and Associate Director of CEER F. Wayne Klaiber, Ph.D. Professor Emeritus and Faculty Affiliate of BEC Research Assistants Shiyun Wang and Heath Gieselman Authors Pavana Vennapusa, David White, Wayne Klaiber, and Shiyun Wang Sponsored by the Iowa Highway Research Board (IHRB Project TR-621) Preparation of this report was financed in part through funds provided by the Iowa Department of Transportation through its research management agreement with the Institute for Transportation and the Center for Earthworks Engineering Research. (InTrans Project 10-380) A report from Center for Earthworks Engineering Research (CEER) Iowa State University 2711 South Loop Drive, Suite 4600 Ames, IA 50010-8664 Phone: 515-294-7910 Fax: 515-294-0467 www.ceer.iastate.edu TABLE OF CONTENTS ACKNOWLEDGMENTS ............................................................................................................ XI EXECUTIVE SUMMARY ........................................................................................................ XIII INTRODUCTION ...........................................................................................................................1 BACKGROUND .............................................................................................................................3 Geosynthetic Reinforced Soil Abutment Systems ...............................................................4 Rail Road Flat Cars for Low-Volume Road Bridges .........................................................12 LABORATORY AND IN SITU TESTING METHODS .............................................................14 Laboratory Test Methods ...................................................................................................14 In Situ Testing ....................................................................................................................18 RESULTS AND ANALYSIS FROM FIELD PROJECTS ...........................................................26 Bridge 1 ― Olympic Avenue, Buchanan County, Iowa ...................................................26 Bridge 2 ― 250th Street, Buchanan County, Iowa ...........................................................44 Recommendations for Future GRS Bridge Construction Projects ..................................103 KEY FINDINGS, CONCLUSIONS, AND RECOMMENDATIONS .......................................105 REFERENCES ............................................................................................................................109 APPENDIX A: MIRAFI® 500X TECHNICAL DATA SHEET .................................................113 APPENDIX B: VIBRATING WIRE EARTH PRESSURE READINGS FROM UNDER THE FOOTING – BRIDGE 2 ..................................................................................................114
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