TABLEOFCONTENTS-VolumeIICHAPTER8REINFORCED (STEEPENED)SOIL SLOPESPROJECTEVALUATION.... 8-18.18-1INTRODUCTION8.2.8-1REINFORCEDSOILSLOPESYSTEMS.8-18.2.1TypesofSystems8-28.2.2Construction Materials8.3DESIGN APPROACH.8-2.8-28.3.1UseConsiderations.8.3.2.8-4Design of Reinforcementfor Compaction Aid8.3.3.8-4DesignofReinforcementforSteepeningSlopesandSlopeRepair8.3.48-6Computer-AssistedDesign8.3.5.8-8Evaluation of External Stability8.48-11CONSTRUCTIONSEQUENCE8.58-15TREATMENTOFOUTWARDFACE.8.5.18-15Grass Type Vegetation8.5.28-16Soil Bioengineering (Woody Vegetation)8-198.5.3Armored8.6..8-20DESIGNDETAILS8.6.1..8-20Guardrail and Traffic Barriers.8.6.2..8-20Drainage Considerations.8.6.3..8-21Obstructions8-218.7CASEHISTORIES8.7.18-21TheDickeyLakeRoadway Grade Improvement Project8.7.28-24Salmon-Lost Trail Roadway Widening Project8.7.38-26CannonCreekAlternateEmbankmentConstructionProject8.7.48-27Pennsylvania SR54RoadwayRepairProject..8-298.7.5Massachusetts Turnpike-Use of Soil Bioengineering8.7.6242-foot High 1H:1VReinforced Soil Slope for Airport Runway.8-32Extension..8.8.8-34STANDARDRSS DESIGNS...9-1CHAPTER9DESIGNOFREINFORCEDSOILSLOPES9.1.9-1INTRODUCTION9.29-3REINFORCEDSLOPEDESIGNGUIDELINES9.2.1Step 1- Establish the geometric, loading, and performance.9-3requirements for design..9.2.2.9-3Step2-Determinetheengineeringproperties ofthe in-situsoils..9.2.3Step 3 - Determine the properties of reinforced fill and, if different, the9-5retainedfill9.2.49-5 Step 4 - Evaluate design parameters for the reinforcement .9-59.2.5Step 5- Check unreinforced stability.9.2.69-7Step 6 -Design reinforcement to provide a stable slope9.2.79-16Step 7-Check external stability.9.2.89-18Step 8 - Seismic stability..9.2.9Step9-Evaluaterequirementsfor subsurfaceandsurfacewaterrunoff9-19controlFHWANHI-10-025Tableof ContentsMSEWallsandRSS-VolIINovember2009
TABLE OF CONTENTS – Volume II CHAPTER 8 REINFORCED (STEEPENED) SOIL SLOPES PROJECT EVALUATION . 8-1 8.1 INTRODUCTION . 8-1 8.2 REINFORCED SOIL SLOPE SYSTEMS . 8-1 8.2.1 Types of Systems . 8-1 8.2.2 Construction Materials . 8-2 8.3 DESIGN APPROACH . 8-2 8.3.1 Use Considerations . 8-2 8.3.2 Design of Reinforcement for Compaction Aid . 8-4 8.3.3 Design of Reinforcement for Steepening Slopes and Slope Repair . 8-4 8.3.4 Computer-Assisted Design . 8-6 8.3.5 Evaluation of External Stability . 8-8 8.4 CONSTRUCTION SEQUENCE . 8-11 8.5 TREATMENT OF OUTWARD FACE. 8-15 8.5.1 Grass Type Vegetation. 8-15 8.5.2 Soil Bioengineering (Woody Vegetation) . 8-16 8.5.3 Armored . 8-19 8.6 DESIGN DETAILS . 8-20 8.6.1 Guardrail and Traffic Barriers . 8-20 8.6.2 Drainage Considerations . 8-20 8.6.3 Obstructions . 8-21 8.7 CASE HISTORIES . 8-21 8.7.1 The Dickey Lake Roadway Grade Improvement Project . 8-21 8.7.2 Salmon-Lost Trail Roadway Widening Project . 8-24 8.7.3 Cannon Creek Alternate Embankment Construction Project . 8-26 8.7.4 Pennsylvania SR 54 Roadway Repair Project . 8-27 8.7.5 Massachusetts Turnpike - Use of Soil Bioengineering . 8-29 8.7.6 242-foot High 1H:1V Reinforced Soil Slope for Airport Runway Extension. 8-32 8.8 STANDARD RSS DESIGNS . 8-34 CHAPTER 9 DESIGN OF REINFORCED SOIL SLOPES . 9-1 9.1 INTRODUCTION . 9-1 9.2 REINFORCED SLOPE DESIGN GUIDELINES. 9-3 9.2.1 Step 1 - Establish the geometric, loading, and performance requirements for design. 9-3 9.2.2 Step 2 - Determine the engineering properties of the in-situ soils. 9-3 9.2.3 Step 3 - Determine the properties of reinforced fill and, if different, the retained fill. 9-5 9.2.4 Step 4 - Evaluate design parameters for the reinforcement . 9-5 9.2.5 Step 5 - Check unreinforced stability. 9-5 9.2.6 Step 6 - Design reinforcement to provide a stable slope . 9-7 9.2.7 Step 7 - Check external stability . 9-16 9.2.8 Step 8 - Seismic stability. 9-18 9.2.9 Step 9 - Evaluate requirements for subsurface and surface water runoff control . 9-19 FHWA NHI-10-025 Table of Contents MSE Walls and RSS – Vol II v November 2009
9.39-23COMPUTERASSISTEDDESIGN9.49-24PROJECTCOSTESTIMATESCHAPTER1OCONTRACTINGMETHODSANDSPECIFICATIONS10-1FORMSEWALLSANDSLOPES10.110-2POLICYDEVELOPMENT.10-210.2SYSTEMORCOMPONENTAPPROVALS10.3DESIGNANDPERFORMANCECRITERIA10-510.4..10-5AGENCYORSUPPLIERDESIGN.10-610.4.1Plan and Elevation Sheets.10-710.4.2Facing/Panel Details10-710.4.3DrainageFacilities/SpecialDetails10-710.4.4Design Computations.10-710.4.5GeotechnicalReport..10-810.4.6ConstructionSpecifications10.510-8ENDRESULTDESIGNAPPROACH10-910.5.1GeometricRequirements10-910.5.2GeotechnicalRequirements10-910.5.3Structural andDesignRequirements.10-1010.5.4PerformanceRequirements10.6.10-10STANDARDDESIGNS.10-1010.6.1MSEWStandardDesigns10-1210.6.2RSSStandardDesigns10.7REVIEWANDAPPROVALS10-1310.8CONSTRUCTIONSPECIFICATIONSANDSPECIALPROVISIONSFORMSEWANDRSSCONSTRUCTION.10-1410.9EXAMPLESPECIFICATIONFORMSEWALLS10-1510.10CONSTRUCTIONSPECIFICATIONSFORREINFORCED10-41SLOPESYSTEMS10.10.1SpecificationGuidelinesForRSSConstruction(AgencyDesign)10-4210.10.210-46Specification for ErosionControl Mat or Blanket10.10.310-48SpecificationforGeosyntheticDrainageComposite.10.10.4Specification Guidelines forGeosynthetic Reinforced Soil..10-52Slope Systems..11-1CHAPTER11FIELDINSPECTIONANDPERFORMANCEMONITORING11-111.1PRECONSTRUCTIONREVIEWS.11-311.1.1 Plans and Specifications..11-311.1.2ReviewofSiteConditionsandFoundationRequirements11.211-11PREFABRICATEDMATERIALSINSPECTION11.2.1PrecastConcreteElements..11-1111.2.2 Reinforcing Elements...11-13.11-1511.2.3FacingJointMaterials....11-1511.2.4Reinforced Backfill11.311-16CONSTRUCTIONCONTROL11-1611.3.1 Leveling Pad11.3.2ErectionofFacingElements.11-16FHWANHI-10-025Tableof ContentsviMSEWallsandRSS-VolIINovember2009
9.3 COMPUTER ASSISTED DESIGN . 9-23 9.4 PROJECT COST ESTIMATES . 9-24 CHAPTER 10 CONTRACTING METHODS AND SPECIFICATIONS FOR MSE WALLS AND SLOPES. 10-1 10.1 POLICY DEVELOPMENT. 10-2 10.2 SYSTEM OR COMPONENT APPROVALS . 10-2 10.3 DESIGN AND PERFORMANCE CRITERIA . 10-5 10.4 AGENCY OR SUPPLIER DESIGN . 10-5 10.4.1 Plan and Elevation Sheets. 10-6 10.4.2 Facing/Panel Details . 10-7 10.4.3 Drainage Facilities/Special Details. 10-7 10.4.4 Design Computations. 10-7 10.4.5 Geotechnical Report. 10-7 10.4.6 Construction Specifications . 10-8 10.5 END RESULT DESIGN APPROACH . 10-8 10.5.1 Geometric Requirements . 10-9 10.5.2 Geotechnical Requirements . 10-9 10.5.3 Structural and Design Requirements . 10-9 10.5.4 Performance Requirements . 10-10 10.6 STANDARD DESIGNS . 10-10 10.6.1 MSEW Standard Designs . 10-10 10.6.2 RSS Standard Designs . 10-12 10.7 REVIEW AND APPROVALS. 10-13 10.8 CONSTRUCTION SPECIFICATIONS AND SPECIAL PROVISIONS FOR MSEW AND RSS CONSTRUCTION . 10-14 10.9 EXAMPLE SPECIFICATION FOR MSE WALLS . 10-15 10.10 CONSTRUCTION SPECIFICATIONS FOR REINFORCED SLOPE SYSTEMS . 10-41 10.10.1 Specification Guidelines For RSS Construction (Agency Design) 10-42 10.10.2 Specification for Erosion Control Mat or Blanket. 10-46 10.10.3 Specification for Geosynthetic Drainage Composite. 10-48 10.10.4 Specification Guidelines for Geosynthetic Reinforced Soil Slope Systems . 10-52 CHAPTER 11 FIELD INSPECTION AND PERFORMANCE MONITORING. 11-1 11.1 PRECONSTRUCTION REVIEWS. 11-1 11.1.1 Plans and Specifications . 11-3 11.1.2 Review of Site Conditions and Foundation Requirements . 11-3 11.2 PREFABRICATED MATERIALS INSPECTION . 11-11 11.2.1 Precast Concrete Elements. 11-11 11.2.2 Reinforcing Elements. 11-13 11.2.3 Facing Joint Materials. 11-15 11.2.4 Reinforced Backfill . 11-15 11.3 CONSTRUCTION CONTROL . 11-16 11.3.1 Leveling Pad . 11-16 11.3.2 Erection of Facing Elements . 11-16 FHWA NHI-10-025 Table of Contents MSE Walls and RSS – Vol II vi November 2009
11-2211.3.3ReinforcedFillPlacement,Compaction11-2511.3.4 Placement of ReinforcingElements..11.3.5Placementof SubsequentFacingCourses (SegmentalFacings)11-2611-3511.4PERFORMANCEMONITORINGPROGRAMS11-3511.4.1PurposeofMonitoringProgram.11-3611.4.2 Limited Monitoring Program..11.4.3ComprehensiveMonitoringProgram11-3711-3711.4.4ProgramImplementation11.4.5Data Interpretation11-40REFERENCES.R-1APPENDICESAPPENDIXALRFDLOADCOMBINATIONSANDLOADFACTORS.ANDLOADFACTORFORPERMANENTLOADSA-1..B-1APPENDIX BDETERMINATIONOFPULLOUTRESISTANCEFACTORS..B.1..B-1EMPIRICALPROCEDURESTODETERMINEF*ANDα.B.2EXPERIMENTALPROCEDURESTODETERMINEF*ANDα..B-2B.3CONNECTIONRESISTANCEANDSTRENGTHOFPARTIALANDFULLFRICTIONSEGMENTALBLOCK/REINFORCEMENTFACINGCONNECTIONS..B-5B.4CONNECTIONRESISTANCEDEFINEDWITH.B-12SHORT-TERM TESTINGB.5.B-15REFERENCESAPPENDIXC.C-1TYPICALDIMENSIONSOFSTEELREINFORCEMENTSAPPENDIX DDETERMINATIONOFCREEPSTRENGTHREDUCTIONFACTOR...D-1D.1BACKGROUND... D-1D.2STEP-BY-STEPPROCEDURESFOREXTRAPOLATINGSTRESSRUPTUREDATA--CONVENTIONALMETHODD-5D.3STEP-BY-STEPPROCEDURESFOREXTRAPOLATINGSTRESSRUPTUREDATA -- STEPPEDISOTHERMALMETHOD(SIM)...D-.10D.4D-13DETERMINATIONOFRFCR...D.5USEOFCREEPDATAFROM"SIMILAR"PRODUCTSAND.D-14EVALUATIONOFPRODUCTLINESD.6CREEPEXTRAPOLATIONEXAMPLESUSINGSTRESS...E-16RUPTUREDATA..E-16D.6.1StressRuptureExtrapolationExampleD.7.E-20REFERENCESFHWA NHI-10-025Tableof ContentsviiMSEWallsandRSS-VolIINovember2009
11.3.3 Reinforced Fill Placement, Compaction . 11-22 11.3.4 Placement of Reinforcing Elements. 11-25 11.3.5 Placement of Subsequent Facing Courses (Segmental Facings) . 11-26 11.4 PERFORMANCE MONITORING PROGRAMS . 11-35 11.4.1 Purpose of Monitoring Program . 11-35 11.4.2 Limited Monitoring Program . 11-36 11.4.3 Comprehensive Monitoring Program . 11-37 11.4.4 Program Implementation . 11-37 11.4.5 Data Interpretation . 11-40 REFERENCES .R-1 APPENDICES APPENDIX A LRFD LOAD COMBINATIONS AND LOAD FACTORS, AND LOAD FACTOR FOR PERMANENT LOADS . A-1 APPENDIX B DETERMINATION OF PULLOUT RESISTANCE FACTORS .B-1 B.1 EMPIRICAL PROCEDURES TO DETERMINE F* AND α .B-1 B.2 EXPERIMENTAL PROCEDURES TO DETERMINE F* AND α .B-2 B.3 CONNECTION RESISTANCE AND STRENGTH OF PARTIAL AND FULL FRICTION SEGMENTAL BLOCK/REINFORCEMENT FACING CONNECTIONS .B-5 B.4 CONNECTION RESISTANCE DEFINED WITH SHORT-TERM TESTING .B-12 B.5 REFERENCES .B-15 APPENDIX C TYPICAL DIMENSIONS OF STEEL REINFORCEMENTS .C-1 APPENDIX D DETERMINATION OF CREEP STRENGTH REDUCTION FACTOR . D-1 D.1 BACKGROUND . D-1 D.2 STEP-BY-STEP PROCEDURES FOR EXTRAPOLATING STRESS RUPTURE DATA - CONVENTIONAL METHOD . D-5 D.3 STEP-BY-STEP PROCEDURES FOR EXTRAPOLATING STRESS RUPTURE DATA - STEPPED ISOTHERMAL METHOD (SIM) . D-10 D.4 DETERMINATION OF RFCR . D-13 D.5 USE OF CREEP DATA FROM "SIMILAR" PRODUCTS AND EVALUATION OF PRODUCT LINES . D-14 D.6 CREEP EXTRAPOLATION EXAMPLES USING STRESS RUPTURE DATA .E-16 D.6.1 Stress Rupture Extrapolation Example .E-16 D.7 REFERENCES .E-20 FHWA NHI-10-025 Table of Contents MSE Walls and RSS – Vol II vii November 2009
APPENDIXEEXAMPLECALCULATIONSE.1MBWUnitFacedMSEWallwithBrokenBackSlopingFill andLiveE.1-1Load Surcharge,ReinforcedwithGeogrid..E.2Bearing Check for Sloping Toe Conditions, with and without Water.... E.2-1E.3SegmentalPrecastPanelMSEWall withSlopingBackfill Surcharge,E.3-1Reinforced with Steel StripsE.4Segmental Precast Panel MSE Wall with Level Backfill and Live Load.E.4-1Surcharge, Reinforced with Steel Bar Mats.E.5TrueBridgeAbutmentwithSegmentalPrecastPanelMSEWall..E.5-1ReinforcedwithSteelStrips.E.6.E.6-1Traffic Barrier Impact Loading on Top of an MSE WallE.7E.7-1Seismic Loading:..Psuedo-StaticAnalysis.E.8Reinforced Soil Slope Design --Road Widening.E.8-1E.9Reinforced Soil SlopeDesign --High Slope for New Road Construction.E.9-1E.10Reinforced Soil Slope Design -- Facing Stability CalculationE.10-1APPENDIXFOTHERDESIGNPROCEDURESANDANALSISMODELSF.1.F-2ASDProcedureand the Simplified MethodF.2.F-3CoherentGravityMethod..F-5F.3National Concrete Masonry Association ProcedureF.4..F-5GRSF.5.F-7FHWAStructural Stiffness Method.F.6.F-8K-Stiffness MethodF.7F-11DeepPatchFHWA NHI-10-025TableofContentsviliNovember2009MSEWallsandRSS-VolII
APPENDIX E EXAMPLE CALCULATIONS E.1 MBW Unit Faced MSE Wall with Broken Back Sloping Fill and Live Load Surcharge, Reinforced with Geogrid . E.1-1 E.2 Bearing Check for Sloping Toe Conditions, with and without Water . E.2-1 E.3 Segmental Precast Panel MSE Wall with Sloping Backfill Surcharge, Reinforced with Steel Strips .E.3-1 E.4 Segmental Precast Panel MSE Wall with Level Backfill and Live Load Surcharge, Reinforced with Steel Bar Mats.E.4-1 E.5 True Bridge Abutment with Segmental Precast Panel MSE Wall, Reinforced with Steel Strips .E.5-1 E.6 Traffic Barrier Impact Loading on Top of an MSE Wall .E.6-1 E.7 Seismic Loading . . . ., Psuedo-Static Analysis. E.7-1 E.8 Reinforced Soil Slope Design - Road Widening .E.8-1 E.9 Reinforced Soil Slope Design - High Slope for New Road Construction . E.9-1 E.10 Reinforced Soil Slope Design - Facing Stability Calculation .E.10-1 APPENDIX F OTHER DESIGN PROCEDURES AND ANALSIS MODELS F.1 ASD Procedure and the Simplified Method .F-2 F.2 Coherent Gravity Method .F-3 F.3 National Concrete Masonry Association Procedure .F-5 F.4 GRS .F-5 F.5 FHWA Structural Stiffness Method. F-7 F.6 K-Stiffness Method .F-8 F.7 Deep Patch .F-11 FHWA NHI-10-025 Table of Contents MSE Walls and RSS – Vol II viii November 2009
LISTOFTABLES-VolumeIITable 8-1....8-14RSS Slope Facing Options (after Collin, 1996)9-25Table 9-1.Estimated Project Costs..11-2Table 11-1.Outline of MSE/RSSField InspectionChecklist.Table 11-2.11-5Checklist forDrawingReview.Table 11-3...11-7ChecklistforSpecificationCompliance.11-30Table 11-4.Out-of-Tolerance Conditions and Possible Causes..Table 11-5..11-32ChecklistforConstruction..Table 11-6.11-38Possible Instruments for Monitoring Reinforced Soil Structures.FHWA NHI-10-025TableofContentsMSEWallsandRSS-VolIIixNovember2009
LIST OF TABLES – Volume II Table 8-1. RSS Slope Facing Options (after Collin, 1996). 8-14 Table 9-1. Estimated Project Costs. . 9-25 Table 11-1. Outline of MSE/RSS Field Inspection Checklist. . 11-2 Table 11-2. Checklist for Drawing Review. 11-5 Table 11-3. Checklist for Specification Compliance. . 11-7 Table 11-4. Out-of-Tolerance Conditions and Possible Causes. 11-30 Table 11-5. Checklist for Construction. . 11-32 Table 11-6. Possible Instruments for Monitoring Reinforced Soil Structures. . 11-38 FHWA NHI-10-025 Table of Contents MSE Walls and RSS – Vol II ix November 2009