《高等土力学》课程教学资源（书籍文献）Design and Construction of Mechanically Stabilized Earth Walls and Reinforced Soil Slopes（Volume I）

U. S. Department of TransportationPublicationNo.FHWA-NHI-10-024FederalHighwayAdministrationFHWA GEC 011-VolumeINovember2009NHI Courses No. 132042 and 132043Design and Construction ofMechanically Stabilized Earth Wallsand Reinforced Soil Slopes - Volume IDevelopedfollowing:AASHTOLRFDBridgeDesignandAASHTOLRFDBridgeConstructionSpecifications, 4hEdition,2007,Specifications, 2ndEdition,2004, withwith 2008 and 2009 Interims.2006, 2007, 2008, and 2009 Interims.NHiNATIONALHIGHWAYINSTITUTE

U. S. Department of Transportation Publication No. FHWA-NHI-10-024 Federal Highway Administration FHWA GEC 011 – Volume I November 2009 NHI Courses No. 132042 and 132043 Design and Construction of Mechanically Stabilized Earth Walls and Reinforced Soil Slopes – Volume I Developed following: AASHTO LRFD Bridge Design and AASHTO LRFD Bridge Construction Specifications, 4th Edition, 2007, Specifications, 2nd Edition, 2004, with with 2008 and 2009 Interims. 2006, 2007, 2008, and 2009 Interims

TechnicalReportDocumentationPage1.REPORT NO.2. GOVERNMENT3.RECIPIENTS CATALOG NOACCESSIONNO.FHWA-NHI-10-024FHWA GEC 011-Vol I4.TITLEANDSUBTITLE5.REPORTDATENovember2009Design of Mechanically Stabilized Earth Walls6.PERFORMINGORGANIZATIONCODEandReinforcedSoil Slopes-VolumeI7.AUTHOR(S)8.PERFORMINGORGANIZATIONREPORTNO.Ryan R. Berg, P.E.; Barry R. Christopher.Ph.D., P.E. and Naresh C. Samtani, Ph.D.P.E9.PERFORMINGORGANIZATIONNAMEANDADDRESS10.WORKUNITNORyan R.Berg & Associates, Inc.11.CONTRACTORGRANTNO2190 Leyland AlcoveDTFH61-06-D-00019/T-06-001Woodbury,MN5512512. SPONSORING AGENCY NAME AND ADDRESS13.TYPEOFREPORT&PERIODCOVEREDNationalHighwayInstituteFederal Highway Administration14.SPONSORINGAGENCYCODEU.S.Department of TransportationWashington, D.C.15.SUPPLEMENTARYNOTESFHWA Technical Consultants: Rich Barrows, P.E., Silas Nichols, P.E., and Daniel Alzamora, P.E.TechnicalConsultant:JamesG.Collin,Ph.D.,P.E16.ABSTRACTThis manual is the reference text used for the FHWA NHI courses No. 132042 and 132043onMechanicallyStabilizedEarthWallsandReinforcedSoilSlopesandreflectscurrentpracticeforthedesign,constructionandmonitoringofthesestructures.Thismanualwasprepared to enable the engineer to identify and evaluate potential applications of MSE wallsand RsS as an alternative to other construction methods and as a means to solve constructionproblems.The scope is sufficientlybroad to beof valuefor specifications specialists,construction andcontractingpersonnel responsibleforconstruction inspection,developmentof material specifications and contracting methods. With the aid of this text, the engineershould be able to properly select, design, specify, monitor and contract for the construction ofMSEwallsandRSSembankments.The MSE wall design within this manual is based upon Load and Resistance Factor Design(LRFD) procedures. This manual is a revision (to LRFD) and an update to the FHWA NHI-00-043manual (which was based upon allowable stress design (ASD)procedures)17.KEYWORDS18. DISTRIBUTION STATEMENTDesign, Load and Resistance Factor DesignNorestrictions(LRFD), analysis,performancecriteria,Mechanically Stabilized Earth (MSE)Walls,Reinforced Soil Slopes(RSS),soilreinforcement,geosynthetics,specifications,contractingmethods19. SECURITY CLASSIF20.SECURITY CLASSIF21.NO.OF PAGES22Unclassified306Unclassified

Technical Report Documentation Page 1. REPORT NO. 2. GOVERNMENT 3. RECIPIENT'S CATALOG NO. ACCESSION NO. FHWA-NHI-10-024 FHWA GEC 011-Vol I 4. TITLE AND SUBTITLE 5. REPORT DATE November 2009 Design of Mechanically Stabilized Earth Walls and Reinforced Soil Slopes – Volume I 6. PERFORMING ORGANIZATION CODE 7. AUTHOR(S) 8. PERFORMING ORGANIZATION REPORT NO. Ryan R. Berg, P.E.; Barry R. Christopher, Ph.D., P.E. and Naresh C. Samtani, Ph.D., P.E. 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. WORK UNIT NO. Ryan R. Berg & Associates, Inc. 11. CONTRACT OR GRANT NO. 2190 Leyland Alcove DTFH61-06-D-00019/T-06-001 Woodbury, MN 55125 12. SPONSORING AGENCY NAME AND ADDRESS 13. TYPE OF REPORT & PERIOD COVERED National Highway Institute Federal Highway Administration 14. SPONSORING AGENCY CODE U.S. Department of Transportation Washington, D.C. 15. SUPPLEMENTARY NOTES FHWA Technical Consultants: Rich Barrows, P.E., Silas Nichols, P.E., and Daniel Alzamora, P.E. Technical Consultant: James G. Collin, Ph.D., P.E. 16. ABSTRACT This manual is the reference text used for the FHWA NHI courses No. 132042 and 132043 on Mechanically Stabilized Earth Walls and Reinforced Soil Slopes and reflects current practice for the design, construction and monitoring of these structures. This manual was prepared to enable the engineer to identify and evaluate potential applications of MSE walls and RSS as an alternative to other construction methods and as a means to solve construction problems. The scope is sufficiently broad to be of value for specifications specialists, construction and contracting personnel responsible for construction inspection, development of material specifications and contracting methods. With the aid of this text, the engineer should be able to properly select, design, specify, monitor and contract for the construction of MSE walls and RSS embankments. The MSE wall design within this manual is based upon Load and Resistance Factor Design (LRFD) procedures. This manual is a revision (to LRFD) and an update to the FHWA NHI- 00-043 manual (which was based upon allowable stress design (ASD) procedures). 17. KEY WORDS 18. DISTRIBUTION STATEMENT Design, Load and Resistance Factor Design No restrictions. (LRFD), analysis, performance criteria, Mechanically Stabilized Earth (MSE) Walls, Reinforced Soil Slopes (RSS), soil reinforcement, geosynthetics, specifications, contracting methods 19. SECURITY CLASSIF. 20. SECURITY CLASSIF. 21. NO. OF PAGES 22 Unclassified Unclassified 306

SICONVERSIONFACTORSAPPROXIMATECONVERSIONSFROMSIUNITSSymbolMultiply ByTo FindSymbolWhen You KnowLENGTH0.039inmmmillimetersinchesft3.28feetmmeters1.09yardsydmmeterskm0.621mikilometersmilesAREAin?mm?0.0016squaremillimeterssquare inchesft2m?10.764square feetsquare metersm?yd?1.195square yardssquare metersha2.47hectaresacacreskm?mi?0.386square kilometerssquaremilesVOLUMEmlfl oz0.034fluid ouncesmillimeters1galliters0.264gallonsm3ft335.71cubic meterscubic feetm3yd'1.307cubic yardscubic metersMASS0.035ggramsozounces1bkg2.202kilogramspoundsTEMPERATURE°℃°F1.8 C + 32CelsiusFahrenheitWEIGHTDENSITYkN/m36.36pcfkilonewton/cubicmpoundforce/cubicfootFORCEandPRESSUREorSTRESSN0.2251bfpoundforcenewtonskN2251bf kilonewtonspoundforcekPa0.145psikilopascalspoundforce / sq in.kPa20.9psfkilopascalspoundforce / sq ft

SI CONVERSION FACTORS APPROXIMATE CONVERSIONS FROM SI UNITS Symbol When You Know Multiply By To Find Symbol LENGTH mm m m km millimeters meters meters kilometers 0.039 3.28 1.09 0.621 inches feet yards miles in ft yd mi AREA mm2 m2 m2 ha km2 square millimeters square meters square meters hectares square kilometers 0.0016 10.764 1.195 2.47 0.386 square inches square feet square yards acres square miles in2 ft2 yd2 ac mi2 VOLUME ml l m3 m3 millimeters liters cubic meters cubic meters 0.034 0.264 35.71 1.307 fluid ounces gallons cubic feet cubic yards fl oz gal ft3 yd3 MASS g kg grams kilograms 0.035 2.202 ounces pounds oz lb TEMPERATURE °C Celsius 1.8 C + 32 Fahrenheit °F kN/m3 WEIGHT DENSITY kilonewton / cubic m 6.36 poundforce / cubic foot pcf FORCE and PRESSURE or STRESS N kN kPa kPa newtons kilonewtons kilopascals kilopascals 0.225 225 0.145 20.9 poundforce poundforce poundforce / sq in. poundforce / sq ft lbf lbf psi psf

PREFACEEngineers and specialty material suppliers have been designing reinforced soil structures forthe past 35 years. Currently,many state DOTs are transitioning their design of substructuresfrom Allowable Stress Design (ASD) to Load and Resistance Factor Design (LRFD)procedures.This manual is based upon LRFD for MSE wall structures. It has been updated from the2001FHWANHI-00-043manual.In addition to revision of thewall design toLRFDprocedures, expanded discussion on wall detailing and general updates throughout themanual are provided.The primary purpose of this manual is to support educational programsconductedbyFHWAfortransportationagencies.A second purpose of equal importance is to serve as the FHWA standard reference forhighway projects involving MSE wall and reinforced soil structures.This Mechanically Stabilized Earth Walls (MSE) and Reinforced Soil Slopes (RSS),Designand Construction Guidelines Manual which is an update of the current FHWA NHI-00-043,has evolved from the following AASHTO and FHWA references:AASHTO LRFD Bridge Design Specifications, 4th Edition, 2007, with 2008 and 2009InterimRevisions.Earth Retaining Structures, by B.F. Tanyu, P.J. Sabatini, and R.R. Berg, FHWA-NHI-07-071 (2008).AASHTO LRFD Bridge Construction Specifications, 2nd Edition, 2004, with 2006Interim Revisions.Geosynthetic Design and Construction Guidelines, by R.D.Holtz, B.R. Christopher, andR.R. Berg, FHWA HI-07-092 (2008).Guidelines for Design, Specification, and Contracting of Geosynthetic MechanicallyStabilized Earth Slopes onFirmFoundations,byR.R.Berg,FHWA-SA-93-025,January1993.Reinforced Soil Structures - Volume I, Design and Construction Guidelines - Volume II,Summary of Research and Systems Information, by B.R.Christopher,S.A.Gill, J.P.Giroud, J.K.Mitchell,F.Schlosser, and J.Dunnicliff, FHWARD 89-043 (1990)· Design and Construction Monitoring of Mechanically Stabilized Earth Structures, byJ.A.DiMaggio, FHWA, (1994)AASHTO Bridge T-15 Technical Committee unpublished working drafts for the updateof Section11.0of theAASHTOLRFDBridgeDesign Specifications.FHWA NHI-10-024iiiMSE Walls and RSS - VolINovember2009

PREFACE Engineers and specialty material suppliers have been designing reinforced soil structures for the past 35 years. Currently, many state DOTs are transitioning their design of substructures from Allowable Stress Design (ASD) to Load and Resistance Factor Design (LRFD) procedures. This manual is based upon LRFD for MSE wall structures. It has been updated from the 2001 FHWA NHI-00-043 manual. In addition to revision of the wall design to LRFD procedures, expanded discussion on wall detailing and general updates throughout the manual are provided. The primary purpose of this manual is to support educational programs conducted by FHWA for transportation agencies. A second purpose of equal importance is to serve as the FHWA standard reference for highway projects involving MSE wall and reinforced soil structures. This Mechanically Stabilized Earth Walls (MSE) and Reinforced Soil Slopes (RSS), Design and Construction Guidelines Manual which is an update of the current FHWA NHI-00-043, has evolved from the following AASHTO and FHWA references: C AASHTO LRFD Bridge Design Specifications, 4th Edition, 2007, with 2008 and 2009 Interim Revisions. C Earth Retaining Structures, by B.F. Tanyu, P.J. Sabatini, and R.R. Berg, FHWA-NHI-07- 071 (2008). C AASHTO LRFD Bridge Construction Specifications, 2nd Edition, 2004, with 2006 Interim Revisions. C Geosynthetic Design and Construction Guidelines, by R.D. Holtz, B.R. Christopher, and R.R. Berg, FHWA HI-07-092 (2008). C Guidelines for Design, Specification, and Contracting of Geosynthetic Mechanically Stabilized Earth Slopes on Firm Foundations, by R.R. Berg, FHWA-SA-93-025, January 1993. C Reinforced Soil Structures - Volume I, Design and Construction Guidelines - Volume II, Summary of Research and Systems Information, by B.R. Christopher, S.A. Gill, J.P. Giroud, J.K. Mitchell, F. Schlosser, and J. Dunnicliff, FHWA RD 89-043 (1990). C Design and Construction Monitoring of Mechanically Stabilized Earth Structures, by J.A. DiMaggio, FHWA, (1994). C AASHTO Bridge T-15 Technical Committee unpublished working drafts for the update of Section 11.0 of the AASHTO LRFD Bridge Design Specifications. FHWA NHI-10-024 MSE Walls and RSS – Vol I iii November 2009

The authors recognize the efforts and contributions of Messrs. Richard Barrows, P.E., SilasNichols, P.E., and Daniel Alzamora P.E, who were the FHWA Technical Consultants for thiswork.The authors also recognize the contributions of the other Technical Consultants onthisproject.Theyare:·Tony Allen, P.E. of Washington DOT:Christopher Benda, P.E. of Vermont DOT·James Brennan, P.E.of Kansas DOT.James Collin, Ph.D., P.E. of The Collin Group:JerryDiMaggio, P.E.oftheNational Academy of Sciences·Kenneth L.Fishman, Ph.D.,P.E.of Earth Reinforcement Testing, Inc:Kathryn Griswell, P.E. of CALTRANSJohn Guido, P.E. of Ohio DOT.Dan Johnston, P.E.of South Dakota DOT::DovLeshchinsky,Ph.D.oftheUniversityofDelawareMichael Simac, P.E. of Earth Improvement Technologies, Inc.James L.Withiam, Ph.D., P.E.of D'Appolonia Engineers.And theauthors acknowledge the contributions ofthefollowing industry associations:.Association of Metallically Stabilized Earth (AMSE).Geosynthetic Materials Association (GMA)National Concrete MasonryAssociation (NCMA)·A special acknowledgement of Mr.Jerry A.DiMaggio,P.E.who was theFHWA TechnicalConsultant for most of the above referenced publications.Mr.DiMaggio's guidance andinput to this and the previous works has been invaluable.Lastly, the authors wish to acknowledge the extensive work of the late Victor Elias, P.E. forhis vital contributions and significant effort as Lead Author in preparing the earlier two(1997, 2001)versions of this manual, and as the author of the earlier companion manuals oncorrosion/degradationofsoilreinforcements.Mr.Eliaswasinstrumentalintheintroductionand implementation of reinforced soil technology in the U.S., as a Vice President for TheReinforced Earth Company from 1974 to 1985. He was instrumental in research, refinementof designmethods, and standards of practice and codes for MSEwalls, as a Consultantfrom1985until2006FHWA NHI-10-024ivMSE Walls and RSS- Vol INovember2009

The authors recognize the efforts and contributions of Messrs. Richard Barrows, P.E., Silas Nichols, P.E., and Daniel Alzamora P.E. who were the FHWA Technical Consultants for this work. The authors also recognize the contributions of the other Technical Consultants on this project. They are: C Tony Allen, P.E. of Washington DOT C Christopher Benda, P.E. of Vermont DOT C James Brennan, P.E. of Kansas DOT C James Collin, Ph.D., P.E. of The Collin Group C Jerry DiMaggio, P.E. of the National Academy of Sciences C Kenneth L. Fishman, Ph.D., P.E. of Earth Reinforcement Testing, Inc. C Kathryn Griswell, P.E. of CALTRANS C John Guido, P.E. of Ohio DOT C Dan Johnston, P.E. of South Dakota DOT C Dov Leshchinsky, Ph.D. of the University of Delaware C Michael Simac, P.E. of Earth Improvement Technologies, Inc. C James L. Withiam, Ph.D., P.E. of D’Appolonia Engineers And the authors acknowledge the contributions of the following industry associations: C Association of Metallically Stabilized Earth (AMSE) C Geosynthetic Materials Association (GMA) C National Concrete Masonry Association (NCMA) A special acknowledgement of Mr. Jerry A. DiMaggio, P.E. who was the FHWA Technical Consultant for most of the above referenced publications. Mr. DiMaggio's guidance and input to this and the previous works has been invaluable. Lastly, the authors wish to acknowledge the extensive work of the late Victor Elias, P.E. for his vital contributions and significant effort as Lead Author in preparing the earlier two (1997, 2001) versions of this manual, and as the author of the earlier companion manuals on corrosion/degradation of soil reinforcements. Mr. Elias was instrumental in the introduction and implementation of reinforced soil technology in the U.S., as a Vice President for The Reinforced Earth Company from 1974 to 1985. He was instrumental in research, refinement of design methods, and standards of practice and codes for MSE walls, as a Consultant from 1985 until 2006. FHWA NHI-10-024 MSE Walls and RSS – Vol I iv November 2009

TABLEOFCONTENTS-VolumeI1-1CHAPTER1INTRODUCTION1.11-1OBJECTIVES1-11.1.1Scope1-21.1.2SourceDocuments1-31.1.3Terminology1.21-4HISTORICALDEVELOPMENT1.31-12LOADANDRESISTANCEFACTORDESIGN(LRFD)2-1CHAPTER2SYSTEMSANDPROJECTEVALUATION2.12-1APPLICATIONS2-12.1.1 MSEWalls2-42.1.2Reinforced Soil Slopes.2.22-6ADVANTAGESANDPOTENTIALDISADVANTAGES2-62.2.1AdvantagesofMechanicallyStabilizedEarth(MSE)Walls2-62.2.2AdvantagesofReinforcedSoilSlopes(RSS)2-72.2.3Potential Disadvantages2.3.2-7RELATIVE COSTS.2.42-10DESCRIPTIONOFMSE/RSSSYSTEMS2.4.12-10Systems Differentiation2.4.22-11Types of Systems.2.4.32-12Facing Systems.2.4.42-16Reinforcement Types.2.4.52-17Reinforced Fill Materials2.4.62-18AppurtenantMaterialsofConstruction2.52-18CONSTRUCTIONSEQUENCE.2-182.5.1ConstructionofMSEWsystemswithprecastfacings2.5.2.2-24Construction of MSEsystems withFlexibleFacings2.5.3RSS Construction2-282.62-28SITE EVALUATION.2.6.12-28Site Exploration.2.6.22-30Field Reconnaissance...2-302.6.3Subsurface Exploration2.6.42-32Laboratory Testing..2.6.52-33Foundation Soils2.72-34PROJECTEVALUATION.2.7.12-34Structure SelectionFactors2-352.7.2Geologic and TopographicConditions2.7.32-36Environmental Conditions2.7.42-37Size and Nature of Structure.2.7.5.2-38Aesthetics2.7.62-38QuestionableApplications2.82-38ESTABLISHMENTOFPROJECTCRITERIA2-392.8.1Alternates2.8.22-39Facing Considerations...FHWA NHI-10-024Tableof ContentsMSEWallsandRSS-VolINovember2009

TABLE OF CONTENTS – Volume I CHAPTER 1 INTRODUCTION . 1-1 1.1 OBJECTIVES. 1-1 1.1.1 Scope . 1-1 1.1.2 Source Documents . 1-2 1.1.3 Terminology. 1-3 1.2 HISTORICAL DEVELOPMENT . 1-4 1.3 LOAD AND RESISTANCE FACTOR DESIGN (LRFD) . 1-12 CHAPTER 2 SYSTEMS AND PROJECT EVALUATION . 2-1 2.1 APPLICATIONS . 2-1 2.1.1 MSE Walls . 2-1 2.1.2 Reinforced Soil Slopes. 2-4 2.2 ADVANTAGES AND POTENTIAL DISADVANTAGES. 2-6 2.2.1 Advantages of Mechanically Stabilized Earth (MSE) Walls. 2-6 2.2.2 Advantages of Reinforced Soil Slopes (RSS). 2-6 2.2.3 Potential Disadvantages . 2-7 2.3 RELATIVE COSTS. 2-7 2.4 DESCRIPTION OF MSE/RSS SYSTEMS. 2-10 2.4.1 Systems Differentiation . 2-10 2.4.2 Types of Systems . 2-11 2.4.3 Facing Systems . 2-12 2.4.4 Reinforcement Types . 2-16 2.4.5 Reinforced Fill Materials . 2-17 2.4.6 Appurtenant Materials of Construction . 2-18 2.5 CONSTRUCTION SEQUENCE . 2-18 2.5.1 Construction of MSEW systems with precast facings . 2-18 2.5.2 Construction of MSE systems with Flexible Facings . 2-24 2.5.3 RSS Construction. 2-28 2.6 SITE EVALUATION . 2-28 2.6.1 Site Exploration . 2-28 2.6.2 Field Reconnaissance . 2-30 2.6.3 Subsurface Exploration . 2-30 2.6.4 Laboratory Testing . 2-32 2.6.5 Foundation Soils . 2-33 2.7 PROJECT EVALUATION. 2-34 2.7.1 Structure Selection Factors . 2-34 2.7.2 Geologic and Topographic Conditions . 2-35 2.7.3 Environmental Conditions . 2-36 2.7.4 Size and Nature of Structure. 2-37 2.7.5 Aesthetics. 2-38 2.7.6 Questionable Applications . 2-38 2.8 ESTABLISHMENT OF PROJECT CRITERIA . 2-38 2.8.1 Alternates . 2-39 2.8.2 Facing Considerations. 2-39 FHWA NHI-10-024 Table of Contents MSE Walls and RSS – Vol I v November 2009

2.8.312-40PerformanceCriteria.2.8.4DesignLife.2-462.92-46PROPRIETARYASPECTS2.102-47CASEHISTORIES--MSEWALLS.2-472.10.1Mn/DOTCrosstownProject MSEWalls.2-492.10.2VeteransMemorialOverpassTrueAbutmentMSEWalls.2-502.10.3 SEATACRunwayExtension Wall2-512.10.4GuanellaPassRoadwayReconstructionCHAPTER3SOILREINFORCEMENTPRINCIPLES.3-1AND SYSTEMDESIGNPROPERTIES3.1.3-1OVERVIEW3.2ESTABLISHMENTOFENGINEERINGPROPERTIESBASEDONSITE3-2EXPLORATIONANDTESTING3-23.2.11Reinforced Fill Soil..3-83.2.2RetainedBackfill and NaturalRetained Soil3-93.2.3Electrochemical Properties3.3.3-10REINFORCEDSOILCONCEPTS.3-103.3.1StressTransferMechanisms.3.3.23-12Mode of Reinforcement Action3-123.3.3GeometricCharacteristics..3.4SOILREINFORCEMENTINTERACTIONUSINGNORMALIZED3-13CONCEPTS3-133.4.1EvaluationofPulloutPerformance3.4.2Estimate of the Reinforcement Pullout Capacity in MSE Structures ... 3-163-213.4.3Interface Shear.3.53-22ESTABLISHMENTOFSTRUCTURALDESIGNPROPERTIES3-22Strength Properties of Steel Reinforcements3.5.13-283.5.2StrengthPropertiesofGeosyntheticReinforcement.3-313.5.2.a Ultimate Tensile Strength, Tult..3-313.5.2.bInstallationDamageReductionFactor,RFD.3-323.5.2.cCreepReductionFactor,RFcR3-333.5.2.dDurabilityReductionFactor, RF.3-383.5.2.eDurabilityReductionFactor,RFp,atWallFaceUnit3-383.5.2.fLRFDGeosyntheticResistanceFactor,.3-393.5.2.g Preliminary Design Reduction Factor, RF.3-403.5.2.h Serviceability Limit State3.63-41FACING MATERIALS.3-413.6.11PrecastConcretePanels3-413.6.1.a Segmental Panels..3-423.6.1.b Full-Height Panels .3.6.2.3-43ModularBlock Wall (MBW)Units.3-463.6.3Welded Wire Mesh Facing3.6.43-47Geosynthetic Wrap-Around Facing3.6.53-47OtherFacings3.6.6..3-50Two-Stage Facings.FHWA NHI-10-024Table of ContentsviMSEWallsandRSS-VolINovember2009

2.8.3 Performance Criteria . 2-40 2.8.4 Design Life. 2-46 2.9 PROPRIETARY ASPECTS . 2-46 2.10 CASE HISTORIES - MSE WALLS . 2-47 2.10.1 Mn/DOT Crosstown Project MSE Walls. 2-47 2.10.2 Veterans Memorial Overpass True Abutment MSE Walls. 2-49 2.10.3 SEATAC Runway Extension Wall . 2-50 2.10.4 Guanella Pass Roadway Reconstruction. 2-51 CHAPTER 3 SOIL REINFORCEMENT PRINCIPLES AND SYSTEM DESIGN PROPERTIES . 3-1 3.1 OVERVIEW . 3-1 3.2 ESTABLISHMENT OF ENGINEERING PROPERTIES BASED ON SITE EXPLORATION AND TESTING . 3-2 3.2.1 Reinforced Fill Soil . 3-2 3.2.2 Retained Backfill and Natural Retained Soil . 3-8 3.2.3 Electrochemical Properties . 3-9 3.3 REINFORCED SOIL CONCEPTS . 3-10 3.3.1 Stress Transfer Mechanisms . 3-10 3.3.2 Mode of Reinforcement Action . 3-12 3.3.3 Geometric Characteristics . 3-12 3.4 SOIL REINFORCEMENT INTERACTION USING NORMALIZED CONCEPTS . 3-13 3.4.1 Evaluation of Pullout Performance . 3-13 3.4.2 Estimate of the Reinforcement Pullout Capacity in MSE Structures . 3-16 3.4.3 Interface Shear . 3-21 3.5 ESTABLISHMENT OF STRUCTURAL DESIGN PROPERTIES . 3-22 3.5.1 Strength Properties of Steel Reinforcements . 3-22 3.5.2 Strength Properties of Geosynthetic Reinforcement. 3-28 3.5.2.a Ultimate Tensile Strength, Tult . 3-31 3.5.2.b Installation Damage Reduction Factor, RFID . 3-31 3.5.2.c Creep Reduction Factor, RFCR . 3-32 3.5.2.d Durability Reduction Factor, RFD. 3-33 3.5.2.e Durability Reduction Factor, RFD, at Wall Face Unit . 3-38 3.5.2.f LRFD Geosynthetic Resistance Factor, . 3-38 3.5.2.g Preliminary Design Reduction Factor, RF . 3-39 3.5.2.h Serviceability Limit State . 3-40 3.6 FACING MATERIALS . 3-41 3.6.1 Precast Concrete Panels . 3-41 3.6.1.a Segmental Panels . 3-41 3.6.1.b Full-Height Panels . 3-42 3.6.2 Modular Block Wall (MBW) Units . 3-43 3.6.3 Welded Wire Mesh Facing . 3-46 3.6.4 Geosynthetic Wrap-Around Facing . 3-47 3.6.5 Other Facings . 3-47 3.6.6 Two-Stage Facings. 3-50 FHWA NHI-10-024 Table of Contents MSE Walls and RSS – Vol I vi November 2009

4-1CHAPTER4DESIGNOFMSEWALLS4.14-1DESIGNMETHODOLOGYANDANALYSISMETHODS4-14.1.1LoadandResistanceFactorDesign(LRFD)Platform4-24.1.2Analysis Methods..4.2..4-3LOADSANDLOADCOMBINATIONS4.3.4-6DESIGNOFMSEWALLSUSINGLRFDMETHODOLOGY.4-74.3.1Design Steps.4.4MSE WALLS DESIGNGUIDELINES.4-9.4-94.4.1Step1-EstablishProjectRequirements4-94.4.2Step2-Establish Project Parameters4.4.3Step3-EstimateWallEmbedment Depth &Reinforcement Length...4-104.4.4Step 4 - Define Nominal Loads4-114.4.5Step 5 - Summarize Load Combinations, Load Factors, and Resistance4-17Factors.4.4.64-18Step 6- Evaluate External Stability.4-194.4.6.a Evaluate Sliding Stability.4-224.4.6.bEvaluateEccentricity4-264.4.6.cEvaluateBearingonFoundation..4-314.4.6.dSettlementEstimate4.4.7.4-31Step7-EvaluateInternal Stability.4-324.4.7.a Select Type of Reinforcement.4-334.4.7.bDefineCriticalSlipSurface4-354.4.7.cDefine Unfactored Loads4-384.4.7.d Establish Vertical Layout of Soil Reinforcements...4-394.4.7.e CalculateFactored TensileForces in Reinforcements...4-474.4.7.fCalculateSoilReinforcementResistance....4-494.4.7.g Select Grade of &/or Number of Elements at Each Level4-494.4.7.h Internal Stability with Respect to Pullout Failure4-524.4.7.iCheckConnectionStrength..4-574.4.7.j Lateral Movements....4-574.4.7.kVerticalMovementandBearingPads.4-584.4.8Step8-DesignofFacingElements...4-584.4.8.aDesign ofConcrete, Steel, and TimberFacings.4-594.4.8.bDesign of FlexibleWallFacings.4-594.4.9Step9-AssessOverall Stability4-614.4.10 Step 10 - Assess Compound Stability4-654.4.11 Step 11-WallDrainage Systems.4-654.11.aSurfaceDrainage4-654.11.b Surface Water Runoff4.11.cScour4-654.5..4-66TEMPORARYWALLS4.6.4-66DESIGNCHECKLIST..4.7.4-80COMPUTER-AIDEDDESIGN4.8.4-80VENDOR4.94-80STANDARDMSEWDESIGNSFHWA NHI-10-024Tableof ContentsviiMSEWallsandRSS-VolINovember2009

CHAPTER 4 DESIGN OF MSE WALLS . 4-1 4.1 DESIGN METHODOLOGY AND ANALYSIS METHODS . 4-1 4.1.1 Load and Resistance Factor Design (LRFD) Platform . 4-1 4.1.2 Analysis Methods. 4-2 4.2 LOADS AND LOAD COMBINATIONS . 4-3 4.3 DESIGN OF MSE WALLS USING LRFD METHODOLOGY . 4-6 4.3.1 Design Steps. 4-7 4.4 MSE WALLS DESIGN GUIDELINES . 4-9 4.4.1 Step 1 - Establish Project Requirements . 4-9 4.4.2 Step 2 - Establish Project Parameters . 4-9 4.4.3 Step 3 - Estimate Wall Embedment Depth & Reinforcement Length . 4-10 4.4.4 Step 4 - Define Nominal Loads . 4-11 4.4.5 Step 5 - Summarize Load Combinations, Load Factors, and Resistance Factors . 4-17 4.4.6 Step 6 - Evaluate External Stability. 4-18 4.4.6.a Evaluate Sliding Stability . 4-19 4.4.6.b Evaluate Eccentricity . 4-22 4.4.6.c Evaluate Bearing on Foundation. 4-26 4.4.6.d Settlement Estimate . 4-31 4.4.7 Step 7 - Evaluate Internal Stability . 4-31 4.4.7.a Select Type of Reinforcement . 4-32 4.4.7.b Define Critical Slip Surface . 4-33 4.4.7.c Define Unfactored Loads . 4-35 4.4.7.d Establish Vertical Layout of Soil Reinforcements. 4-38 4.4.7.e Calculate Factored Tensile Forces in Reinforcements. 4-39 4.4.7.f Calculate Soil Reinforcement Resistance . 4-47 4.4.7.g Select Grade of &/or Number of Elements at Each Level . 4-49 4.4.7.h Internal Stability with Respect to Pullout Failure. 4-49 4.4.7.i Check Connection Strength . 4-52 4.4.7.j Lateral Movements . 4-57 4.4.7.k Vertical Movement and Bearing Pads . 4-57 4.4.8 Step 8 - Design of Facing Elements. 4-58 4.4.8.a Design of Concrete, Steel, and Timber Facings . 4-58 4.4.8.b Design of Flexible Wall Facings. 4-59 4.4.9 Step 9 - Assess Overall Stability. 4-59 4.4.10 Step 10 - Assess Compound Stability . 4-61 4.4.11 Step 11 - Wall Drainage Systems . 4-65 4.11.a Surface Drainage. 4-65 4.11.b Surface Water Runoff . 4-65 4.11.c Scour . 4-65 4.5 TEMPORARY WALLS . 4-66 4.6 DESIGN CHECKLIST . 4-66 4.7 COMPUTER-AIDED DESIGN . 4-80 4.8 VENDOR. 4-80 4.9 STANDARD MSEW DESIGNS . 4-80 FHWA NHI-10-024 Table of Contents MSE Walls and RSS – Vol I vii November 2009

5-1CHAPTER5MSEWALLDESIGNDETAILS5-15.1TOPOFWALLELEMENTS5-15.1.1Copings.5-45.1.2Traffic Barriers.5-45.1.3Parapets..5-45.1.4Post and Beam Barriers.5-65.1.5DrainageRelated toTopof WallElements5.2BOTTOMOFWALLELEMENTS...5-65.3..5-8DRAINAGE...5-95.3.1Internal Drainage Systems5.3.25-17ExternalDrainage.5-245.3.3Filtration andDrainage SystemComponentRequirements.5.3.45-34Maintenance of Drainage.5.45-35INTERNAL DETAILS...5.4.15-35ContactBetweenDissimilarMetals.5.4.25-35Vertical Obstructions in Reinforced Soil Mass5.4.35-42Horizontal Obstructions inReinforced Soil Mass5-445.4.4Wall Face Penetrations5.4.55-46Slip Joints..5-475.4.6Wall Curves.5-515.4.7Wall Corners.5-525.4.8Two-StageFacing5.55-54WALLINITIATIONS AND TERMINATIONS5.65-56AESTHETICS6-1CHAPTER6DESIGNOFMSEWALLSWITHCOMPLEXGEOMETRICS.6-36.1BRIDGEABUTMENTS6-36.1.1MSEWAbutmentsonSpreadFootings.6.1.2MSEWAbutments on StubFootings SupportedbyDeepFoundations.6-6through Reinforced Wall Fill6.1.36-10Alternative Configuration of MSEWalls at BridgeAbutments6-116.1.4ProtectionofMSEWall atAbutments6.2.6-13SUPERIMPOSED(TIERED)MSEWALLS6-136.2.1 2-Tier Superimposed Wall6-156.2.2SuperimposedWallswithMorethan2-Tiers6.3.6-16WALLSWITHUNEVENREINFORCEMENTLENGTHS6.4.6-17BACK-TO-BACK(BBMSE)WALLS...6.5SHOREDMSEWALLSFORSTEEPTERRAINSANDLOWVOLUME6-19ROADS.6.66-26STABLEFEATURE MSE (SFMSE)WALLS.7-1CHAPTER7DESIGNOFMSEWALLSFOREXTREMEEVENTS.7-17.1SEISMICEVENTS.7-17.1.1 External Stability.7-97.1.2Internal Stability..7-117.1.2.a Tensile Failure7.1.2.b Pullout Failure.7-12FHWA NHI-10-024Table of ContentsviliMSEWallsandRSS-VolINovember2009

CHAPTER 5 MSE WALL DESIGN DETAILS . 5-1 5.1 TOP OF WALL ELEMENTS . 5-1 5.1.1 Copings . 5-1 5.1.2 Traffic Barriers. 5-4 5.1.3 Parapets. 5-4 5.1.4 Post and Beam Barriers. 5-4 5.1.5 Drainage Related to Top of Wall Elements . 5-6 5.2 BOTTOM OF WALL ELEMENTS . 5-6 5.3 DRAINAGE. 5-8 5.3.1 Internal Drainage Systems . 5-9 5.3.2 External Drainage . 5-17 5.3.3 Filtration and Drainage System Component Requirements. 5-24 5.3.4 Maintenance of Drainage. 5-34 5.4 INTERNAL DETAILS . 5-35 5.4.1 Contact Between Dissimilar Metals. 5-35 5.4.2 Vertical Obstructions in Reinforced Soil Mass . 5-35 5.4.3 Horizontal Obstructions in Reinforced Soil Mass . 5-42 5.4.4 Wall Face Penetrations . 5-44 5.4.5 Slip Joints. 5-46 5.4.6 Wall Curves . 5-47 5.4.7 Wall Corners . 5-51 5.4.8 Two-Stage Facing . 5-52 5.5 WALL INITIATIONS AND TERMINATIONS . 5-54 5.6 AESTHETICS. 5-56 CHAPTER 6 DESIGN OF MSE WALLS WITH COMPLEX GEOMETRICS . 6-1 6.1 BRIDGE ABUTMENTS . 6-3 6.1.1 MSEW Abutments on Spread Footings . 6-3 6.1.2 MSEW Abutments on Stub Footings Supported by Deep Foundations through Reinforced Wall Fill . 6-6 6.1.3 Alternative Configuration of MSE Walls at Bridge Abutments . 6-10 6.1.4 Protection of MSE Wall at Abutments . 6-11 6.2 SUPERIMPOSED (TIERED) MSE WALLS. 6-13 6.2.1 2-Tier Superimposed Wall . 6-13 6.2.2 Superimposed Walls with More than 2-Tiers . 6-15 6.3 WALLS WITH UNEVEN REINFORCEMENT LENGTHS . 6-16 6.4 BACK-TO-BACK (BBMSE) WALLS . 6-17 6.5 SHORED MSE WALLS FOR STEEP TERRAINS AND LOW VOLUME ROADS. 6-19 6.6 STABLE FEATURE MSE (SFMSE) WALLS . 6-26 CHAPTER 7 DESIGN OF MSE WALLS FOR EXTREME EVENTS. 7-1 7.1 SEISMIC EVENTS . 7-1 7.1.1 External Stability . 7-1 7.1.2 Internal Stability. 7-9 7.1.2.a Tensile Failure . 7-11 7.1.2.b Pullout Failure. 7-12 FHWA NHI-10-024 Table of Contents MSE Walls and RSS – Vol I viii November 2009

7.1.3 FacingReinforcementConnections7-137.27-14VEHICULARIMPACTEVENTS7-157.2.1Traffic Barriers....7-177.2.2Postand Beam Railings7.37-18FLOODSANDSCOURFHWA NHI-10-024TableofContentsMSE Walls and RSS- VolINovember2009ix

7.1.3 Facing Reinforcement Connections . 7-13 7.2 VEHICULAR IMPACT EVENTS . 7-14 7.2.1 Traffic Barriers. 7-15 7.2.2 Post and Beam Railings . 7-17 7.3 FLOODS AND SCOUR . 7-18 FHWA NHI-10-024 Table of Contents MSE Walls and RSS – Vol I ix November 2009