《高等土力学》课程教学资源（书籍文献）Geotechnical engineering circular No.4（Ground anchors and anchored systems）

Publication No. FHWA-IF-99-015 JUNE 1999 US. Department of Transportation OFFICE OF BRIDGE TECHNOLOGY Federal Highway Administration 400 SEVENTH STREET, SW WASHINGTON, DC 20590 GEOTECHNICAL ENGINEERING CIRCULAR NO. 4 GROUND ANCHORS AND ANCHORED SYSTEMS ENGINEERING CIRCULAR NO. 4. GEOTECHNICAL ENGINEERING CIRCULAR NO. 4. GEOTECHNICAL ENGINEERING CIRCULAR NO. 4. GEOTECHNICAL ENGINEERING CIRCULAR NO. 4. GEOTECHNICAL ENGINEERING CIRCULAR NO. 4. GEOTECHNICAL ENC HLAR NO.4·GEOTECHNICAL ENGINEERING CIRCUL ENGINEERING CIRCUILAR NO. 4 GEOTECH 。 4.GEOTECHNICAL ENGINEERING CI NEERING CIRCULAR NO.4. GEOT GEOTECHNICAL ENGINEERING RING CIRCULAR No.4.GEO STRUCTURAL FOUNDATIONS SOIL & ROCK INSTABILITIES GEOTECHNICAL ENGINEERING 1 Mechanically Stabilized RING CIRCULAR Earth Wall No.4.GEO Ground GEOTECHNICAL Anchors ENGINEERING 00 stone Columns ERING CIRCULAR Roadway. NO.4.GEOTE GEOTECHNICAL ENGINEERING CIR NEERING CIRCULAR NO.4. GEOTECHNIC EARTH RETAINING GROUND MODIFICATION SYSTEMS TECHNIQUES . 4· GEOTECHNICAL ENGINEERING CIRCULAR L ENGINEERING CIRCULAR INO. 4GEOTECHNICAL ENGINEERING CIRCULAR NO. 4. GEOTECHNICAL ENGINEERING CIRCULAR NO. 4 GEOTECHNICAL ENGINEERING CIRCULAR NO. 4. GEOTECHNICAL ENGINEERING CIRCULAR NO. 4 GEOTECHNICAL ENGINEERING CIRCULAR NO. 4. GEOTECHNICAL ENGINEERING CIRCULAR NO. 4. GEOTECHNICAL ENGINEERING CIRCULAR NO. 4. GEOTECHNICAL

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Technical ReportDocumentationPage1. Report No.2.GovernmentAccessionNo3. Recipient's Catalog NoFHWA-IF-99-0154. Title and Subtitle4. Report DateJune 1999GEOTECHNICALENGINEERINGCIRCULARNO.46.Performing Organization CodeGroundAnchorsandAnchoredSystems7. Author(s)8.Performing Organization Report NoP.J. Sabatini, D.G. Pass, R.C. Bachus9. Performing Organization Name and Address10. Work Unit No.(TRAIS)GeoSyntec Consultants1100 Lake Hearn Drive11.ContractorGrantNoDTFH61-94-C-00099Atlanta,Georgia12. Sponsoring Agency Name and Address13 Type of Report and Period CoveredOfficeof BridgeTechnologyTechnical ManualFederal Highway AdministrationHIBT,Ro0m 320314. Sponsoring Agency Code400 Seventh Street, S.WWashingtonD.C.2059015. Supplementary NotesContracting Officer's Technical Representative: Chien-Tan Chang (HIBT)FHWATechnical Consultants: JerryDiMaggio (HIBT),Richard Cheney(HIBT)16. Abstract:Thisdocument presents state-of-the-practiceinformation onthedesign and installation ofcementgrouted ground anchors and anchored systems for highway applications.The anchored systemsdiscussed includeflexible anchored walls, slopes supported using ground anchors, landslidestabilization systems, and structures that incorporate tiedown anchors.This document draws extensively from theFHWA-DP-68-IR (1988) design manual in describingissues such as subsurfaceinvestigation and laboratorytesting,basic anchoringprinciples,groundanchorloadtesting,andinspectionofconstructionmaterialsandmethodsusedforanchoredsystemsThis document provides detailed information on design analyses for ground anchored systemsTopics discussed include selection of design earth pressures, ground anchor design, design ofcorrosionprotectionsystemforgroundanchors,designofwall componentstoresistlateral andvertical loads,evaluationofoverallanchoredsystemstability,and seismicdesignofanchoredsystems.Also included in the document are two detailed design examples and technicalspecifications for ground anchors and foranchored walls.18.Distribution Statemen17.Key WordsNoRestrictions.ThisdocumentisavailabletotheGround anchors, soldier beam and laggingpublic from the National Technical Informationwalls,limitequilibrium,earthpressures,axialService, Springfield, Virginia 22161capacity,tiedowns,seismicdesign,contractingspecifications19. Security Classif. (of this report)20. Security Classification (of this page)21. No. of Pages22.Price281UnclassifiedUnclassifiedFormDOTF1700.7 (8-72)Reproductionof completed page authorized

Technical Report Documentation Page 1. Report No. FHWA-IF-99-015 2. Government Accession No. 3. Recipient’s Catalog No. 4. Title and Subtitle GEOTECHNICAL ENGINEERING CIRCULAR NO. 4 Ground Anchors and Anchored Systems 4. Report Date June 1999 6. Performing Organization Code: 7. Author(s) P.J. Sabatini, D.G. Pass, R.C. Bachus 8. Performing Organization Report No. 9. Performing Organization Name and Address GeoSyntec Consultants 1100 Lake Hearn Drive Atlanta, Georgia 10. Work Unit No.(TRAIS) 11. Contract or Grant No. DTFH61-94-C-00099 12. Sponsoring Agency Name and Address Office of Bridge Technology Federal Highway Administration HIBT, Room 3203 400 Seventh Street, S.W. Washington D.C. 20590 13 Type of Report and Period Covered Technical Manual 14. Sponsoring Agency Code 15. Supplementary Notes Contracting Officer’s Technical Representative: Chien-Tan Chang (HIBT) FHWA Technical Consultants: Jerry DiMaggio (HIBT), Richard Cheney (HIBT) 16. Abstract: This document presents state-of-the-practice information on the design and installation of cement￾grouted ground anchors and anchored systems for highway applications. The anchored systems discussed include flexible anchored walls, slopes supported using ground anchors, landslide stabilization systems, and structures that incorporate tiedown anchors. This document draws extensively from the FHWA-DP-68-IR (1988) design manual in describing issues such as subsurface investigation and laboratory testing, basic anchoring principles, ground anchor load testing, and inspection of construction materials and methods used for anchored systems. This document provides detailed information on design analyses for ground anchored systems. Topics discussed include selection of design earth pressures, ground anchor design, design of corrosion protection system for ground anchors, design of wall components to resist lateral and vertical loads, evaluation of overall anchored system stability, and seismic design of anchored systems. Also included in the document are two detailed design examples and technical specifications for ground anchors and for anchored walls. 17. Key Words Ground anchors, soldier beam and lagging walls, limit equilibrium, earth pressures, axial capacity, tiedowns, seismic design, contracting, specifications 18. Distribution Statement No Restrictions. This document is available to the public from the National Technical Information Service, Springfield, Virginia 22161 19. Security Classif. (of this report) Unclassified 20. Security Classification (of this page) Unclassified 21. No. of Pages 281 22. Price Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

ACKNOWLEDGEMENTSThe authors would like to express their appreciation to Mr. Richard S. Cheney, P.E., of the U.S.Department of Transportation Federal Highway Administration (FHWA) for providing significant technicalassistance and review during preparation of the document.The authors would also like to thank Dr.DonaldA,Bruce, C.Eng of ECO GeoSystems Inc.for providing technical assistance.Dr.Richard Jewell, C.Eng.formerly of GeoSyntec Consultants, assisted in preparing sections of the document and provided technicalassistance.The authors would also like to thank the following individuals who reviewed the document andserved on the Technical Working Group for this project:JamesJ.Brennan,P.E.-KansasDepartment ofTransportation;Chien-Tan Chang,P.E.-FHWA;.Joel Moskowitz,P.E.,of Mueser Rutledge Consulting Engineers-DeepFoundations Institute;Heinz Nierlich of Dywidag-Systems International - Post Tensioning Institute;MontiSingla-FHWA;。JohnP.Tiernan-GeorgiaDepartmentofTransportation;David E.Weatherby of Schnabel Foundation Company-International Association of FoundationDrilling, andShan-Tai Yeh-Colorado Department of Transportation.The authors would also like to acknowledge the following firms and agencies that provided photographs andtechnical information::Dywidag-Systems International;Hayward Baker Inc.;Lang Tendons Inc.;SchnabelFoundationCompany,andWilliamsFormEngineeringCorpFinally,theauthorswouldliketothankMrs.AnnTaylorandMr.MichaelHarrisofGeoSyntecConsultantswho drafted the figures and assisted in the layout of the document

i ACKNOWLEDGEMENTS The authors would like to express their appreciation to Mr. Richard S. Cheney, P.E., of the U.S. Department of Transportation Federal Highway Administration (FHWA) for providing significant technical assistance and review during preparation of the document. The authors would also like to thank Dr. Donald A. Bruce, C.Eng of ECO GeoSystems Inc. for providing technical assistance. Dr. Richard Jewell, C.Eng, formerly of GeoSyntec Consultants, assisted in preparing sections of the document and provided technical assistance. The authors would also like to thank the following individuals who reviewed the document and served on the Technical Working Group for this project: · James J. Brennan, P.E. – Kansas Department of Transportation; · Chien-Tan Chang, P.E. – FHWA; · Joel Moskowitz, P.E., of Mueser Rutledge Consulting Engineers – Deep Foundations Institute; · Heinz Nierlich of Dywidag-Systems International – Post Tensioning Institute; · Monti Singla - FHWA; · John P. Tiernan – Georgia Department of Transportation; · David E. Weatherby of Schnabel Foundation Company – International Association of Foundation Drilling; and · Shan-Tai Yeh – Colorado Department of Transportation. The authors would also like to acknowledge the following firms and agencies that provided photographs and technical information: · Dywidag-Systems International; · Hayward Baker Inc.; · Lang Tendons Inc.; · Schnabel Foundation Company; and · Williams Form Engineering Corp. Finally, the authors would like to thank Mrs. Ann Taylor and Mr. Michael Harris of GeoSyntec Consultants who drafted the figures and assisted in the layout of the document

PREFACEThis document presents state-of-the-practice information on the design and installation of cement-grouted ground anchors and anchored systems for highway applications.Anchored systemsdiscussed include flexible anchored walls, slopes supported using ground anchors, landslidestabilization systems, and structures that incorporate tiedown anchors.This document has been written, in part, to update the design manual titled "Permanent GroundAnchors" (FHWA-DP-68-1R, 1988).This document draws extensively from the FHWA (1988)design manual in describing issues such as subsurface investigation and laboratory testing, basicanchoring principles, ground anchor load testing,and inspection of construction materials andmethods used for anchored systems.Since 1988, advances have been made in design methods andfromnew constructionmaterials, methods, and equipment.Results of anchored system performancemonitoring and research activities conducted since 1989 arealsoincludedinthis document.Mostrecently,research wasconducted under aFHWAresearchcontract on the design and performance of ground anchors and anchored soldier beam and timberlagging walls. As part of that research project, performance data on model- and full-scale anchoredwalls were collected and analyzed. Several of the analysis methods and design procedures that wererecommended based on the results of the research are adopted herein.This research is described inFHWA-RD-98-065(1998),FHWA-RD-98-066 (1998),FHWA-RD-98-067(1998),and FHWA-RD-97-130 (1998)This document provides detailed information on basic principles and design analyses for groundanchors and anchored systems.Topics discussed include selection of design earth pressures, designofcorrosionprotectionsystemsforgroundanchors,designofwallcomponentstoresistlateralandvertical loads, evaluation of overall anchored system stability, and seismic design of anchoredAlso included in the document are two detailed design examples and technicalsystems.specifications for ground anchors and for anchored walls.i

ii PREFACE This document presents state-of-the-practice information on the design and installation of cement￾grouted ground anchors and anchored systems for highway applications. Anchored systems discussed include flexible anchored walls, slopes supported using ground anchors, landslide stabilization systems, and structures that incorporate tiedown anchors. This document has been written, in part, to update the design manual titled "Permanent Ground Anchors" (FHWA-DP-68-1R, 1988). This document draws extensively from the FHWA (1988) design manual in describing issues such as subsurface investigation and laboratory testing, basic anchoring principles, ground anchor load testing, and inspection of construction materials and methods used for anchored systems. Since 1988, advances have been made in design methods and from new construction materials, methods, and equipment. Results of anchored system performance monitoring and research activities conducted since 1989 are also included in this document. Most recently, research was conducted under a FHWA research contract on the design and performance of ground anchors and anchored soldier beam and timber lagging walls. As part of that research project, performance data on model- and full-scale anchored walls were collected and analyzed. Several of the analysis methods and design procedures that were recommended based on the results of the research are adopted herein. This research is described in FHWA-RD-98-065 (1998), FHWA-RD-98-066 (1998), FHWA-RD-98-067 (1998), and FHWA-RD- 97-130 (1998). This document provides detailed information on basic principles and design analyses for ground anchors and anchored systems. Topics discussed include selection of design earth pressures, design of corrosion protection systems for ground anchors, design of wall components to resist lateral and vertical loads, evaluation of overall anchored system stability, and seismic design of anchored systems. Also included in the document are two detailed design examples and technical specifications for ground anchors and for anchored walls

TABLE OFCONTENTSCHAPTER 1INTRODUCTION1.1Purpose1.2AnchoredSystemServiceLife1.3BackgroundCHAPTER2GROUNDANCHORSANDANCHOREDSYSTEMS42.1INTRODUCTION2.2GROUNDANCHORS2.2.1GeneralX2.2.2Types of Ground Anchors62.2.2.16General.2.2.2.2Straight Shaft Gravity-Grouted Ground Anchors.2.2.2.3.8Straight Shaft Pressure-Grouted Ground Anchors2.2.2.4.8Post-grouted Ground Anchors.2.2.2.5Underreamed Anchors..82.2.3Tendon Materials.82.2.3.1.8Steel Bar and Strand Tendons2.2.3.2.9Spacers and Centralizers2.2.3.3Epoxy-Coated Bar and Epoxy-Coated Filled Strand.102.2.3.4Other Anchor Types and Tendon Materials102.2.4Cement Grout2.3ANCHOREDWALLS.112.3.1General2.3.2 Soldier Beam and Lagging Wall.122.3.2.1.12General.2.3.2.2.13SoldierBeam2.3.2.3.14Lagging2.3.2.4.15Construction Sequence.152.3.3 Continuous Wallsi

iii TABLE OF CONTENTS CHAPTER 1 INTRODUCTION.1 1.1 Purpose.1 1.2 Anchored System Service Life .1 1.3 Background .2 CHAPTER 2 GROUND ANCHORS AND ANCHORED SYSTEMS.4 2.1 INTRODUCTION .4 2.2 GROUND ANCHORS.4 2.2.1 General.4 2.2.2 Types of Ground Anchors.6 2.2.2.1 General.6 2.2.2.2 Straight Shaft Gravity-Grouted Ground Anchors.7 2.2.2.3 Straight Shaft Pressure-Grouted Ground Anchors.8 2.2.2.4 Post-grouted Ground Anchors.8 2.2.2.5 Underreamed Anchors.8 2.2.3 Tendon Materials.8 2.2.3.1 Steel Bar and Strand Tendons.8 2.2.3.2 Spacers and Centralizers.9 2.2.3.3 Epoxy-Coated Bar and Epoxy-Coated Filled Strand .10 2.2.3.4 Other Anchor Types and Tendon Materials .10 2.2.4 Cement Grout .11 2.3 ANCHORED WALLS.11 2.3.1 General.11 2.3.2 Soldier Beam and Lagging Wall.12 2.3.2.1 General.12 2.3.2.2 Soldier Beam.13 2.3.2.3 Lagging.14 2.3.2.4 Construction Sequence.15 2.3.3 Continuous Walls.15

TABLE OF CONTENTS (Continued)2.4APPLICATIONSOFGROUNDANCHORS162.4.1 Highway Retaining Walls.162.4.2Slope and Landslide Stabilization..172.4.3TiedownStructuresCHAPTER3SITEINVESTIGATIONANDTESTING..193.1 INTRODUCTION...193.2FIELDRECONNAISSANCE.193.3SUBSURFACEINVESTIGATION..203.3.1General..203.3.2Soil and Rock Stratigraphy.213.3.3.22Groundwater3.4LABORATORYSOILANDROCKTESTING223.4.1.22General3.4.2.23Classification and Index Properties3.4.3.23Shear Strength..233.4.4Consolidation.3.4.5 Electrochemical Criteria..243.5INSITUSOILANDROCKTESTING.24CHAPTER4BASICPRINCIPLESOFANCHOREDSYSTEMDESIGN..264.1GENERALDESIGNCONCEPTSFORANCHOREDWALLS.264.2FAILUREMECHANISMSOFANCHOREDSYSTEMS...284.2.1..28General4.2.2FailureMechanismsof theGroundAnchor284.2.3Failure of Soldier Beams.314.2.4.Failure ofLagging.324.3SELECTIONOFSOILSHEARSTRENGTHPARAMETERSFORDESIGN.......334.3.1General.334.3.2Drained Shear Strength of Granular Soils..334.3.3Undrained Shear Strengthof Normally Consolidated Clay.33iv

TABLE OF CONTENTS (Continued) iv 2.4 APPLICATIONS OF GROUND ANCHORS.16 2.4.1 Highway Retaining Walls.16 2.4.2 Slope and Landslide Stabilization.17 2.4.3 Tiedown Structures.17 CHAPTER 3 SITE INVESTIGATION AND TESTING.19 3.1 INTRODUCTION .19 3.2 FIELD RECONNAISSANCE.19 3.3 SUBSURFACE INVESTIGATION.20 3.3.1 General.20 3.3.2 Soil and Rock Stratigraphy.21 3.3.3 Groundwater.22 3.4 LABORATORY SOIL AND ROCK TESTING.22 3.4.1 General.22 3.4.2 Classification and Index Properties.23 3.4.3 Shear Strength.23 3.4.4 Consolidation.23 3.4.5 Electrochemical Criteria.24 3.5 IN SITU SOIL AND ROCK TESTING.24 CHAPTER 4 BASIC PRINCIPLES OF ANCHORED SYSTEM DESIGN .26 4.1 GENERAL DESIGN CONCEPTS FOR ANCHORED WALLS .26 4.2 FAILURE MECHANISMS OF ANCHORED SYSTEMS.28 4.2.1 General.28 4.2.2 Failure Mechanisms of the Ground Anchor.28 4.2.3 Failure of Soldier Beams .31 4.2.4. Failure of Lagging.32 4.3 SELECTION OF SOIL SHEAR STRENGTH PARAMETERS FOR DESIGN .33 4.3.1 General.33 4.3.2 Drained Shear Strength of Granular Soils.33 4.3.3 Undrained Shear Strength of Normally Consolidated Clay.33

TABLE OF CONTENTS (Continued).344.3.4UndrainedShearStrengthofOverconsolidatedClay4.3.5Drained ShearStrengthofOverconsolidated Clay...344.4EARTHPRESSURES..364.4.1General.364.4.2ActiveandPassiveEarthPressure..364.4.3Earth Pressure at Rest.414.4.4InfluenceofMovement onEarthPressure41CHAPTER5DESIGNOFANCHOREDSYSTEMS.465.1INTRODUCTION.465.2EVALUATIONOFEARTHPRESSURESFORWALLDESIGN....475.2.1Introduction475.2.2Background.48.495.2.3Terzaghiand PeckApparentEarthPressureDiagrams5.2.4RecommendedApparent EarthPressureDiagramfor Sands..505.2.5Recommended Apparent Earth Pressure Diagram for Stiff to Hard Fissured.52Clays5.2.6Recommended Apparent EarthPressureDiagramforSoft toMediumClays575.2.7...60Loading Diagrams for Stratified Soil Profiles..605.2.8Sliding Wedge Analysis Method.5.2.9.62WaterPressures5.2.10 Earth Pressures Due To Surface Loads.645.2.10.1..64Uniform Surcharge Loads..645.2.10.2PointLoads,LineLoads.andStripLoads.5.3GROUNDANCHORDESIGN.655.3.1..65Introduction5.3.2 Location of Critical Potential Failure Surface..655.3.3Calculation of Ground Anchor Loads from Apparent Earth Pressure Diagrams ......655.3.4DesignoftheUnbonded Length..675.3.5..68CompressionAnchors.5.3.6Design of the Anchor Bond Length.69V

TABLE OF CONTENTS (Continued) v 4.3.4 Undrained Shear Strength of Overconsolidated Clay.34 4.3.5 Drained Shear Strength of Overconsolidated Clay.34 4.4 EARTH PRESSURES .36 4.4.1 General.36 4.4.2 Active and Passive Earth Pressure.36 4.4.3 Earth Pressure at Rest.41 4.4.4 Influence of Movement on Earth Pressure.41 CHAPTER 5 DESIGN OF ANCHORED SYSTEMS.46 5.1 INTRODUCTION .46 5.2 EVALUATION OF EARTH PRESSURES FOR WALL DESIGN.47 5.2.1 Introduction.47 5.2.2 Background .48 5.2.3 Terzaghi and Peck Apparent Earth Pressure Diagrams.49 5.2.4 Recommended Apparent Earth Pressure Diagram for Sands.50 5.2.5 Recommended Apparent Earth Pressure Diagram for Stiff to Hard Fissured Clays.52 5.2.6 Recommended Apparent Earth Pressure Diagram for Soft to Medium Clays .57 5.2.7 Loading Diagrams for Stratified Soil Profiles.60 5.2.8 Sliding Wedge Analysis Method.60 5.2.9 Water Pressures.62 5.2.10 Earth Pressures Due To Surface Loads.64 5.2.10.1 Uniform Surcharge Loads.64 5.2.10.2 Point Loads, Line Loads, and Strip Loads.64 5.3 GROUND ANCHOR DESIGN .65 5.3.1 Introduction.65 5.3.2 Location of Critical Potential Failure Surface.65 5.3.3 Calculation of Ground Anchor Loads from Apparent Earth Pressure Diagrams.65 5.3.4 Design of the Unbonded Length.67 5.3.5 Compression Anchors.68 5.3.6 Design of the Anchor Bond Length.69

TABLE OFCONTENTS (Continued)5.3.7SpacingRequirements forGroundAnchors.75..775.3.8Selection of Prestressing Steel Element5.4WALLDESIGNBASEDONLATERALPRESSURES.785.4.1 Design of Soldier Beams and Sheet-Piles.78..815.4.2Design of Lagging for Temporary Support..835.4.3Design of Wales and Permanent Facing5.5LATERALCAPACITYOFEMBEDDEDPORTIONOFWALL.845.5.1.84General.5.5.2EvaluationofUltimatePassiveResistance...845.5.2.1Soldier Beam and Lagging Walls.845.5.2.2ContinuousWalls.865.5.3Depthof PenetrationbelowExcavation....86..875.5.4ComparisonofWang-ReeseandBromsMethodforCompetent Soils.5.6AXIALCAPACITYOFWALI..885.6.1..88Introduction5.6.2..89Axial Load Evaluation5.6.3Axial Capacity Design of Driven Soldier Beams.905.6.3.1General...905.6.3.2..90Effective Stress Analysis for Driven Soldier Beams.5.6.3.3Total Stress Analysis forDriven Soldier Beams in Clays..92.935.6.4Axial Capacity Design Of Drilled-in Soldier Beams5.6.4.1General...935.6.4.2..93Cohesionless Soils..5.6.4.3.94Cohesive Soils5.6.4.4Design Issues for Concrete Backfill of Predrilled Soldier Beam Holes...95...965.7ANCHOREDSLOPESANDLANDSLIDESTABILIZATIONSYSTEMS.5.7.1General.965.7.2Design Concepts..965.7.3Limit Equilibrium Calculations..975.7.3.1OverallApproach97vi

TABLE OF CONTENTS (Continued) vi 5.3.7 Spacing Requirements for Ground Anchors.75 5.3.8 Selection of Prestressing Steel Element .77 5.4 WALL DESIGN BASED ON LATERAL PRESSURES .78 5.4.1 Design of Soldier Beams and Sheet-Piles.78 5.4.2 Design of Lagging for Temporary Support .81 5.4.3 Design of Wales and Permanent Facing .83 5.5 LATERAL CAPACITY OF EMBEDDED PORTION OF WALL.84 5.5.1 General.84 5.5.2 Evaluation of Ultimate Passive Resistance .84 5.5.2.1 Soldier Beam and Lagging Walls .84 5.5.2.2 Continuous Walls.86 5.5.3 Depth of Penetration below Excavation.86 5.5.4 Comparison of Wang-Reese and Broms Method for Competent Soils.87 5.6 AXIAL CAPACITY OF WALL.88 5.6.1 Introduction.88 5.6.2 Axial Load Evaluation.89 5.6.3 Axial Capacity Design of Driven Soldier Beams.90 5.6.3.1 General.90 5.6.3.2 Effective Stress Analysis for Driven Soldier Beams.90 5.6.3.3 Total Stress Analysis for Driven Soldier Beams in Clays.92 5.6.4 Axial Capacity Design Of Drilled-in Soldier Beams.93 5.6.4.1 General.93 5.6.4.2 Cohesionless Soils.93 5.6.4.3 Cohesive Soils .94 5.6.4.4 Design Issues for Concrete Backfill of Predrilled Soldier Beam Holes.95 5.7 ANCHORED SLOPES AND LANDSLIDE STABILIZATION SYSTEMS.96 5.7.1 General.96 5.7.2 Design Concepts.96 5.7.3 Limit Equilibrium Calculations.97 5.7.3.1 Overall Approach.97

TABLE OF CONTENTS (Continued)5.7.3.2.98Method 1 Analysis5.7.3.3.100Method2Analysis5.7.4Modeling Lateral Wall Resistance in Limit Equilibrium Analyses.1015.7.5Comparison of Methods to Evaluate Required Earth Load in Homogeneous.102Soils.1055.8GROUNDMASSSTABILITY5.8.1...105Introduction...1055.8.2Basal Stability.5.8.2.1.105General..1055.8.2.2Evaluation of Bottom Heave Potential in Soft to Medium Clays..1075.8.3Extermal Stability5.8.3.1107Introduction5.8.3.2Evaluation of External Stability Using Limit Equilibrium.108..1095.9TIEDOWNDESIGN..5.9.1 Introduction.1095.9.2UpliftCapacityof RockTiedownAnchors..109..1105.9.3UpliftCapacityof SoilTiedownAnchors5.9.4Design of Tiedown Anchors to Resist Hydrostatic Uplift..1125.10SEISMICDESIGN..113.1135.10.1Introduction5.10.2 Internal Stability Using Pseudo-Static Theory...1135.10.2.1.113Lateral EarthPressure5.10.2.2Wall Design Consideration1165.10.2.3.117Liquefaction.5.10.3 Extermal Stability.1175.10.3.1117Pseudo-Static Analysis5.10.3.2Seismic Deformation Analysis..118价.1195.11 OTHERDESIGNISSUES1195.11.1 Wall and Ground Movements.5.11.2 Drainage Systems for Anchored Walls and Slopes120vii

TABLE OF CONTENTS (Continued) vii 5.7.3.2 Method 1 Analysis.98 5.7.3.3 Method 2 Analysis.100 5.7.4 Modeling Lateral Wall Resistance in Limit Equilibrium Analyses.101 5.7.5 Comparison of Methods to Evaluate Required Earth Load in Homogeneous Soils .102 5.8 GROUND MASS STABILITY.105 5.8.1 Introduction.105 5.8.2 Basal Stability.105 5.8.2.1 General.105 5.8.2.2 Evaluation of Bottom Heave Potential in Soft to Medium Clays .105 5.8.3 External Stability.107 5.8.3.1 Introduction.107 5.8.3.2 Evaluation of External Stability Using Limit Equilibrium.108 5.9 TIEDOWN DESIGN .109 5.9.1 Introduction.109 5.9.2 Uplift Capacity of Rock Tiedown Anchors.109 5.9.3 Uplift Capacity of Soil Tiedown Anchors.110 5.9.4 Design of Tiedown Anchors to Resist Hydrostatic Uplift.112 5.10 SEISMIC DESIGN.113 5.10.1 Introduction.113 5.10.2 Internal Stability Using Pseudo-Static Theory.113 5.10.2.1 Lateral Earth Pressure.113 5.10.2.2 Wall Design Considerations.116 5.10.2.3 Liquefaction.117 5.10.3 External Stability.117 5.10.3.1 Pseudo-Static Analysis.117 5.10.3.2 Seismic Deformation Analysis.118 5.11 OTHER DESIGN ISSUES.119 5.11.1 Wall and Ground Movements.119 5.11.2 Drainage Systems for Anchored Walls and Slopes.120

TABLE OF CONTENTS (Continued)1215.11.3 Wall System Appurtenances.1225.11.4 Resisting the Upper Anchor Test Load1225.11.5 Anchored Walls forFill ApplicationsCHAPTER6CORROSIONCONSIDERATIONSINDESIGN1246.1 INTRODUCTION.1246.2CORROSIONANDEFFECTSONGROUNDANCHORS.....124.1246.2.1 Mechanismof Metallic Corrosion1246.2.2Types of CorrosionforPrestressing Steel.6.3CORROSIONPROTECTIONOFGROUNDANCHORS..1266.3.1 RequirementsofCorrosionProtectionSystems...126.1266.3.2Design of Corrosion Protection Systems6.3.2.1.126General6.3.2.2.131Anchorage Protection6.3.2.3.132Unbonded Tendon Length Protection.6.3.2.4132Tendon Bond Length Protection.6.3.2.5.132Protection Against Stray Currents.6.3.2.6CorrosionProtectionofAnchorsforStructuresSubjecttoHydrostaticUplift..133..1336.4SELECTIONOFCORROSIONPROTECTIONLEVEL.1336.4.1General.1336.4.2Service Life of the Anchored Structure6.4.3..133Aggressivity of the Ground Environment...1356.4.4ConsequencesofFailureoftheAnchored System.6.4.5 Cost for a Higher Level of Protection1356.5CORROSIONOFSTRUCTURALSTEEL,CEMENTGROUT,ANDCONCRETE.135.1356.5.1Corrosion and Protection of Steel Soldier Beams and Sheet Piles.6.5.2Degradation and Protection of Cement Grout and Concrete136vili

TABLE OF CONTENTS (Continued) viii 5.11.3 Wall System Appurtenances.121 5.11.4 Resisting the Upper Anchor Test Load .122 5.11.5 Anchored Walls for Fill Applications.122 CHAPTER 6 CORROSION CONSIDERATIONS IN DESIGN.124 6.1 INTRODUCTION .124 6.2 CORROSION AND EFFECTS ON GROUND ANCHORS.124 6.2.1 Mechanism of Metallic Corrosion.124 6.2.2 Types of Corrosion for Prestressing Steel.124 6.3 CORROSION PROTECTION OF GROUND ANCHORS .126 6.3.1 Requirements of Corrosion Protection Systems.126 6.3.2 Design of Corrosion Protection Systems.126 6.3.2.1 General.126 6.3.2.2 Anchorage Protection.131 6.3.2.3 Unbonded Tendon Length Protection.132 6.3.2.4 Tendon Bond Length Protection.132 6.3.2.5 Protection Against Stray Currents.132 6.3.2.6 Corrosion Protection of Anchors for Structures Subject to Hydrostatic Uplift .133 6.4 SELECTION OF CORROSION PROTECTION LEVEL.133 6.4.1 General.133 6.4.2 Service Life of the Anchored Structure .133 6.4.3 Aggressivity of the Ground Environment.133 6.4.4 Consequences of Failure of the Anchored System.135 6.4.5 Cost for a Higher Level of Protection.135 6.5 CORROSION OF STRUCTURAL STEEL, CEMENT GROUT, AND CONCRETE.135 6.5.1 Corrosion and Protection of Steel Soldier Beams and Sheet Piles.135 6.5.2 Degradation and Protection of Cement Grout and Concrete.136