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Geotechnical Aspects of Pavements Reference Manual

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U.S. Department of Transportation Publication No. FHWA NHI-05-037
Federal Highway Administration
May 2006
NHI Course No. 132040

Sketch showing variation of material quality in a pavement system with ideal drainage (i.e. higher quality in upper layers and lower quality in lower layers)

NOTICE
The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect policy of the Department of Transportation. This report does not constitute a standard, specification, or regulation. The United States Government does not endorse products or manufacturers. Trade or manufacturer's names appear herein only because they are considered essential to the objective of this document.

Technical Report Documentation Page
1. Report No.
NHI-05-037
2. Government Accession No.
 
3. Recipient's Catalog No.
 
4. Title and Subtitle
Geotechnical Aspects of Pavements
5. Report Date
May 2006
6. Performing Organization Code
 
7. Author(s)
Barry R. Christopher, Ph.D., P.E., Charles Schwartz, Ph.D., P.E. and Richard Boudreau, P.E.
8. Performing Organization Report No.
 
9. Performing Organization Name and Address
Ryan R. Berg & Associates, Inc.
2190 Leyland Alcove
Woodbury, MN 55125
10. Work Unit No.
 
11. Contract or Grant No.
DTFH61-02-T-63035
12. Sponsoring Agency Name and Address
National Highway Institute
Federal Highway Administration
U.S. Department of Transportation
Washington, D.C.
13. Type of Report and Period Covered
 
14. Sponsoring Agency Code
 
15. Supplementary Notes
COTR - Larry Jones
FHWA Technical Consultant: Sam Mansukhani, P.E.
Technical Consultants: Ryan R. Berg, P.E. and Bruce Vandre, P.E.
16. Abstract

This is the Reference Manual and Participants Workbook for the FHWA NHI's Course No. 132040 - Geotechnical Aspects of Pavements. The manual covers the latest methods and procedures to address the geotechnical issues in pavement design, construction and performance for new construction, reconstruction, and rehabilitation projects. The manual includes details on geotechnical exploration and characterization of in place and constructed subgrades as well as unbound base/subbase materials. The influence and sensitivity of geotechnical inputs are reviewed with respect to the requirements in past and current AASHTO design guidelines and the mechanistic-empirical design approach developed under NCHRP 1-37A, including the three levels of design input quality. Design details for drainage features and base/subbase material requirements are covered along with the evaluation and selection of appropriate remediation measures for unsuitable subgrades. Geotechnical aspects in relation to construction, construction specifications, monitoring, and performance measurements are discussed.

17. Key Words
geotechnical, mechanistic-empirical, base, subgrades, subbase, construction, pavements
18. Distribution Statement
No restrictions.
19. Security Classification (of this report)
Unclassified
20. Security Classification (of this page)
Unclassified
21. No. of Pages
888
22. Price
 

FHWA Logo Federal Highway Administration   NHI Logo National Highway Institute

Table Of Contents

  1. Introduction
    1. Introduction
    2. A Historical Perspective of Pavement Design
    3. The Pavement System and Typical Pavement Types
      1. Components of a Pavement System
      2. Alternate Types of Pavement
      3. Flexible Pavements
      4. Rigid Pavements
      5. Composite Pavements
      6. Unpaved Roads
    4. Pavement Performance with Ties to Geotechnical Issues
    5. Case Histories of Pavement Geotechnics
      1. Drainage Failure
      2. Collapsible Soils
    6. Concluding Remarks
    7. References
  2. State Agencies
    1. Host Agency
    2. Questionnaire on Geotechnical Practices in Pavement Design
  3. Geotechnical Issues In Pavement Design And Performance
    1. Introduction
    2. Basic Concepts
    3. Key Geotechnical Issues
      1. General Issues
      2. Specific Issues
    4. Sensitivity of Pavement Design
    5. Incorporation of Geotechnical Factors in Pavement Design
      1. Pavement Design Methodologies
      2. The AASHTO Pavement Design Guides
      3. The NCHRP 1-37A Pavement Design Guide
      4. Low Volume Roads
    6. Exercise
    7. References
  4. Geotechnical Exploration And Testing
    1. Introduction
    2. Levels of Geotechnical Exploration for Different Types of Pavement Projects
      1. New Pavement Construction
      2. Reconstruction
      3. Rehabilitation
      4. Subsurface Exploration Program Objectives
    3. Search Available Information
    4. Perform Site Reconnaissance
    5. Plan and Perform the Subsurface Exploration Program
      1. Depth of Influence
      2. Subsurface Exploration Techniques
      3. Remote Sensing
      4. Geophysical Investigations
      5. In-Situ Testing
      6. Borings and Sampling
      7. Guidelines for Idealized Subsurface Exploration Program
    6. Identify Source for Other Geotechnical Components
    7. Subgrade Characterization
      1. Boring Logs
      2. Soil Classification
      3. Subsurface Profile
      4. Select Samples for Laboratory Tests
    8. References
  5. Geotechnical Inputs For Pavement Design
    1. Introduction
    2. Required Geotechnical Inputs
      1. 1993 AASHTO Design Guide
      2. NCHRP 1-37A Design Guide
      3. Other Geotechnical Properties
    3. Physical Properties
      1. Weight-Volume Relationships
      2. Determination of Physical Properties
      3. Identification of Problem Soils
      4. Other Aggregate Tests
    4. Mechanical Properties
      1. California Bearing Ratio (CBR)
      2. Stabilometer (R-Value)
      3. Elastic (Resilient) Modulus
      4. Poisson's Ratio
      5. Structural Layer Coefficients
      6. Modulus of Subgrade Reaction
      7. Interface Friction
      8. Permanent Deformation Characteristics
      9. Coefficient of Lateral Pressure
    5. Thermo-Hydraulic Properties
      1. 1993 AASTHO Guide
      2. NCHRP 1-37A Design Guide
    6. Environmental/Climate Inputs
      1. 1993 AASHTO Guide
      2. NCHRP 1-37A Design Guide
    7. Development of Design Inputs
    8. Exercises
      1. 1993 AASHTO Design Guide - Flexible Pavements
      2. 1993 AASTHO Design Guide - Rigid Pavements
    9. References
  6. Pavement Structural Design And Performance
    1. Introduction
    2. Baseline Designs
      1. 1993 AASHTO Design
      2. NCHRP 1-37A Design
      3. Summary
    3. Soft Subgrade
      1. 1993 AASHTO Design
      2. NCHRP 1-37A Design
      3. Summary
    4. Subgrade Stabilization
    5. Low Quality Base/Subbase
      1. 1993 AASHTO Design
      2. NCHRP 1-37A Design
      3. Summary
    6. Poor Drainage
      1. 1993 AASHTO Design
      2. NCHRP 1-37A Design
      3. Summary
    7. Shallow Bedrock
      1. 1993 AASHTO Design
      2. NCHRP 1-37A Design
    8. Concluding Comments
    9. Exercises
    10. References
  7. Design Details And Subgrade Conditions Requiring Special Design Attention
    1. Introduction
    2. Subsurface Water and Drainage Requirements
      1. Moisture Damage Acceleration
      2. Approaches to Address Moisture in Pavements
      3. Drainage in Pavement Design
      4. Type of Subsurface Drainage
      5. Daylighted Base Sections
      6. Longitudinal Edgedrains
      7. Permeable Bases
      8. Dens-Graded Stabilized Base with Permeable Shoulders
      9. Horizontal Geocomposite Drains
      10. Separator Layers
      11. Performance of Subsurface Drainage
      12. Design of Pavement Drainage
      13. Hydraulic Requirements for the Permeable Layer(s)
      14. Edgedrain Pipe Size and Outlet Spacing Requirements
      15. Separator Layer
      16. Geotextile Separator and Filter Design
    3. Base Layer: Requirements, Stabilization and Reinforcement
      1. Erodibility of Bases
      2. Bound Bases
      3. Modified (or Treated) Bases
      4. Base Reinforcement
    4. Compaction
      1. Compaction Theory
      2. Effect on Soil Properties
    5. Subgrade Conditions Requiring Special Design Attention
      1. Problematic Soil Types
      2. Compressible Soils
      3. Collapsible Soils
      4. Swelling Soils
      5. Subsurface Water
      6. Frost-Susceptible Soils
      7. Summary
    6. Subgrade Improvement and Strengthening
      1. Objectives of Soil Stabilization
      2. Characteristics of Stabilized Soils
      3. Thick Granular Layers
      4. Geotextiles and Geogrids
      5. Admixture Stabilization
      6. Soil Encapsulation
      7. Light-weight Fill
      8. Deep Foundations & Other Foundation Improvement Methods
    7. Recycle
      1. Pavement Recycling
      2. Recycled Waste
    8. References
  8. Construction And Design Verification For Unbound Pavement Materials
    1. Introduction
    2. Specifications
    3. Quality Control and Quality Assurance
      1. QC/QA: Tradition Methods
      2. QC/QA: Emerging Technologies
      3. Risk Acceptance
    4. Construction Techniques
      1. Drainage
      2. Excavation
      3. Hauling and Placement
      4. Field Compaction
      5. Stabilization
      6. Base and Subbase Construction
      7. Pavement Drainage Systems
    5. Performance Monitoring
      1. Pavement Management Systems
      2. Geophysical
      3. Falling Weight Deflectometer
      4. Drainage Inspection
      5. Instrumented Geosynthetics
    6. Post-Construction Issues and Special Cases
    7. References

Appendices

  1. Terminology
  2. Main Highway Project
  3. 1993 AASHTO Design Method
  4. NCHRP 1-37A Design Method
  5. Typical Key for Boring Log Preparation
  6. Determination of Admixture Content for Subgrade Stabilization

List Of Figures

  • 1-01 Basic components of a typical pavement system
  • 1-02 Pavement system with representative alternative features
  • 1-03 Some common variations of flexible pavement sections
  • 1-04 Variations for rigid pavement section
  • 1-05 Typical composite pavement sections
  • 1-06 Normal rutting
  • 1-07 Examples of geotechnical related pavement failures
  • 3-01 Attenuation of load-induced stresses with depth
  • 3-02 Variation of material quality with depth in a pavement system with ideal drainage characteristics
  • 3-03 Sources of moisture in pavement systems
  • 3-04 Impact of subgrade strength on pavement structural design
  • 3-05 Impact of base strength on pavement structural design
  • 3-06 Approximate pavement cost for varying subgrade support conditions
  • 3-07 Slope failure beneath road pavement
  • 3-08 Pavement serviceability in the AASHTO Design Guide
  • 3-09 Sensitivity of 1972 AASHTO flexible pavement design to foundation support quality
  • 3-10 Sensitivity of 1972 AASHTO flexible pavement design to environmental conditions
  • 3-11 Sensitivity of 1972 AASHTO rigid pavement design to foundation stiffness
  • 3-12 Sensitivity of 1986 AASHTO flexible pavement design to subgrade stiffness
  • 3-13 Sensitivity of 1986 AASHTO flexible pavement design to drainage conditions
  • 3-14 Sensitivity of 1986 AASHTO rigid pavement design to subgrade stiffness
  • 3-15 Sensitivity of 1986 AASHTO rigid pavement design to subbase erodibility
  • 3-16 Sensitivity of 1986 AASHTO rigid pavement design to drainage conditions
  • 3-17 Sensitivity of 1986 AASHTO flexible pavement design to reliability level
  • 3-18 Sensitivity of 1986 AASHTO rigid pavement design to reliability level
  • 3-19 Extrapolation of traffic levels in current AASHTO pavement design procedures
  • 4-01 Geotechnical exploration and testing for pavement design
  • 4-02 Soil survey information along the Main Highway pavement alignment
  • 4-03 Typical zone of influence for an asphalt pavement section
  • 4-04 FWD showing: a) typical equipment; b) schematic of procedure; and sketch of deflection bowl for interpretation of results
  • 4-05 Two-dimensional cross-section resistivity profile for detection of sinkholes and caves in limestone
  • 4-06 Representative values of resistivity for different soils
  • 4-07 Resistivity data showing stratigraphic changes
  • 4-08 Representative ground coupled GPR results showing buried utilities and soil profile
  • 4-09 Conductivity results along a road in New Mexico
  • 4-10 Seismic refraction survey
  • 4-11 Rippability versus seismic velocity
  • 4-12 Common in-situ test for pavement evaluation
  • 4-13 CPT log in comparison to SPT data from several locations
  • 4-14 Excavation requirements for frost susceptible soils over undulating rock
  • 4-15 Qualitative relationship between relative subsurface exploration cost & reliability
  • 4-16 Geophysical evaluation used by the Finnish National Road Administration for rehabilitation and reconstruction projects showing a) results from road analysis and b) moisture profile beneath the pavement
  • 4-17 Subsurface exploration log
  • 4-18 The AASHTO and the Unified Soil Classification System
  • 4-19 Particle size limit by different classification systems
  • 4-20 Subsurface profile based on boring data showing cross-sectional view
  • 4-21 Plan view of subsurface information
  • 5-01 Thermal crack prediction from NCHRP 1-37A Design Guide using Level 1 material inputs
  • 5-02 Thermal crack prediction from NCHRP 1-37A Design Guide using Level 3 material inputs
  • 5-03 Relationships between volume and weight/mass of bulk soil
  • 5-04 Typical moisture-density relationship from a standard compaction test
  • 5-05 Laboratory sieves for mechanical analysis of grain size distribution
  • 5-06 Soil hydrometer apparatus
  • 5-07 Representative grain size distribution for several soil types
  • 5-08 Variation of total soil volume and consistency with change in water content for a fine-grained soil
  • 5-09 Liquid limit test device
  • 5-10 Influence of subgrade stiffness on critical pavement strains
  • 5-11 Influence of subgrade stiffness on critical pavement strains
  • 5-12 California Bearing Ratio test device
  • 5-13 Schematic of stabilometer test setup for measuring R-value
  • 5-14 Resilient modulus under cyclic load
  • 5-15 Definition of resilient modulus MR for cyclic triaxial loading
  • 5-16 Triaxial cell set-up for resilient modulus test
  • 5-17 Correlations between subgrade resilient modulus and other soil properties
  • 5-18 Illustration of Poisson's ratio
  • 5-19 Correlation between structural layer coefficients a2 and various strength and stiffness parameters for unbound granular bases
  • 5-20 Correlation between structural layer coefficients a2 and various strength and stiffness parameters for cement treated granular bases
  • 5-21 Correlation between structural layer coefficients a2 and various strength and stiffness parameters for bituminous-treated granular bases
  • 5-22 Correlation between structural layer coefficients a2 and various strength and stiffness parameters for unbound granular subbases
  • 5-23 Coefficients of subgrade reaction k
  • 5-24 Chart for estimating composite modulus of subgrade reaction, k8, Assuming a semi-infinite subgrade depth
  • 5-25 Chart to modify modulus of subgrade reaction to consider effects of rigid foundation near surface
  • 5-26 Chart for estimating relative damage to rigid pavements based on slab thickness and underlying support
  • 5-27 Correction of effective modulus of subgrade reaction for potential loss of subbase support
  • 5-28 Effective dynamic k value determination from d0 and AREA
  • 5-29 Structural model for rigid pavement structural response computations
  • 5-30 Accumulation of permanent deformations with repeated cyclic loading
  • 5-31 Correlation between coefficient of lateral earth pressure and overconsolidation ratio for clays of various plasticity indices
  • 5-32 Horizontal and vertical in-situ stresses during a load-unload-reload path
  • 5-33 Nomograph for estimating swell rate constant
  • 5-34 Chart for estimating potential vertical rise of natural soils
  • 5-35 Chart for estimating frost heave rate for subgrade soil
  • 5-36 Graph for estimating maximum serviceability loss due to frost heave
  • 5-37 Soil water characteristic curves
  • 5-38 Schematic of a constant head permeameter
  • 5-39 Schematic of a falling head permeameter
  • 5-40 Variation of pavement response variable versus distance for given project
  • 6-01 Predicted rutting performance for NCHRP 1-37A baseline flexible pavement design
  • 6-02 Predicted faulting performance for NCHRP 1-37A baseline rigid pavement design
  • 6-03 Predicted rutting performance for soft subgrade scenario
  • 6-04 Predicted faulting performance for soft subgrade scenario
  • 6-05 Summary of rigid pavement sections: soft subgrade scenario
  • 6-06 Example construction costs for rigid pavement sections: soft subgrade scenario
  • 6-07 Summary of rigid pavement sections: soft subgrade scenario
  • 6-08 Example construction costs for rigid pavement sections: soft subgrade scenario
  • 6-09 Effect of lime stabilization on predicted total rutting
  • 6-10 Summary of flexible pavement sections: low quality base scenario
  • 6-11 Predicted faulting performance for low quality base scenario
  • 6-12 Summary of flexible pavement sections: low quality base scenario
  • 6-13 Example construction costs for flexible pavement sections: low quality base scenario
  • 6-14 Summary of rigid pavement sections: low quality base scenario
  • 6-15 Example construction costs for rigid pavement sections: low quality base scenario
  • 6-16 Predicted faulting performance for poor drainage scenario
  • 6-17 Summary of flexible pavement sections: poor drainage scenario
  • 6-18 Example construction costs for flexible pavement sections: poor drainage scenario
  • 6-19 Summary of rigid pavement sections: poor drainage scenario
  • 6-20 Example construction costs for rigid pavement sections: poor drainage scenario
  • 6-21 Summary of costs for example design scenarios: flexible pavement designs
  • 6-22 Summary of costs for example design scenarios: Rigid pavement designs
  • 6-23 Initial service lives for example design scenarios: flexible pavement designs
  • 6-24 Initial service lives for example design scenarios: rigid pavement designs
  • 7-01 The influence of saturation on design life of a pavement system
  • 7-02 Design elements of a drainable pavement system
  • 7-03 Typical AC pavement with a daylighted base
  • 7-04 Typical AC pavement with pipe edgedrains
  • 7-05 Typical PCC pavement with geocomposite edgedrains
  • 7-06 Typical edgedrains for rehabilitation projects
  • 7-07 Dual pipe edgedrain systems showing alternate locations of the parallel collector pipe, either adjacent to or beneath the drain line
  • 7-08 Recommended design of PCC pavement with a nonerodible dense-graded base and permeable shoulder
  • 7-09 Time factor for 50 percent drainage
  • 7-10 Rainfall intensity in inches/hour for a 2-year, 1-hour storm event
  • 7-11 Effect of compaction energy on compaction curves
  • 7-12 Laboratory compaction curves for different soil
  • 7-13 Effect of compacted water content on soil fabric for clays
  • 7-14 Strength as measured by CBR and dry density vs. water content for laboratory impact compaction
  • 7-15 Stiffness as a function of compactive effort and water content
  • 7-16 Shrinkage as a function of water content and type of compaction
  • 7-17 Guide to collapsible soil behavior
  • 7-18 Estimated location of swelling soils
  • 7-19 Elements of frost heave
  • 7-20 Average rate of heave versus % fines for natural soil gradations
  • 7-21 Thickness design curves with geosynthetics for a) single and b) dual wheel loads
  • 7-22 Effect of lime content on engineering properties of a CH clay
  • 8-01 Nuclear densometer
  • 8-02 Process control, field density and moisture
  • 8-03 Lightweight deflectometer
  • 8-04 Underdrain installation
  • 8-05 Self-loading scraper
  • 8-06 Track-mounted excavator
  • 8-07 Articulated dump truck
  • 8-08 Bulldozer
  • 8-09 Motor grader
  • 8-10 Earth moving conveyor system
  • 8-11 Stress distribution under rollers over different foundations
  • 8-12 Smooth drum roller
  • 8-13 Sheepsfoot roller
  • 8-14 Impact roller
  • 8-15 Compaction efficiency
  • 8-16 Roadway stabilizer/mixer

List Of Tables

  • 1-01 Geotechnical influences on major distresses in flexible pavements
  • 1-02 Geotechnical influences on major distresses in rigid pavements
  • 1-03 Geotechnical influences on major distresses in rehabilitated pavements
  • 3-01 Major material types in pavement systems
  • 3-02 Stabilization methods for pavements
  • 3-03 Recommended value for Regional Factor R
  • 3-04 Ranges of structural coefficients from agency survey
  • 3-05 Flexible pavement baseline conditions for 1986 AASHTO sensitivity study
  • 3-06 Rigid pavement baseline conditions for 1986 AASHTO sensitivity study
  • 3-07 Suggested levels of reliability for various functional classifications
  • 3-08 Reliability factors for use in Equation 3.10
  • 4-01 Sources of topographic and geological data for identifying landform boundaries
  • 4-02 Falling weight deflectometer
  • 4-03 Surface resistivity
  • 4-04 Ground penetrating radar
  • 4-05 Electromagnetic conductivity
  • 4-06 Mechanical wave using seismic refraction
  • 4-07 In-situ for subsurface exploration in pavement design and construction
  • 4-08 Standard penetration test
  • 4-09 Dynamic cone penetrometer
  • 4-10 Cone penetrometer
  • 4-11 Subsurface exploration-exploratory boring methods
  • 4-12 Frequently-used standards for field investigations
  • 4-13 Classification of soils
  • 4-14 Summary of soil characteristics as a pavement material
  • 4-15 Minimum laboratory testing requirements for pavement designs
  • 5-01 Required geotechnical inputs for flexible pavement design using the 1993 AASHTO Guide
  • 5-02 Required geotechnical inputs for rigid pavement design using the 1993 AASHTO Guide
  • 5-03 Geotechnical mechanical property inputs required for the flexible pavement design procedure in the NCHRP 1-37A Design Guide
  • 5-04 Geotechnical mechanical property inputs required for the rigid pavement design procedure in the NCHRP 1-37A Design Guide
  • 5-05 Thermo-hydraulic inputs required for the NCHRP 1-37A Design Guide
  • 5-06 Distress model material properties required for the NCHRP 1-37A Design Guide
  • 5-07 Terms in weight-volume relations
  • 5-08 Unit weight-volume relationships
  • 5-09 Typical porosity, void ratio, and unit weight values for soils in their natural state
  • 5-10 Specific gravity of soil and aggregate solids
  • 5-11 Moisture content
  • 5-12 Unit weight
  • 5-13 Compaction characteristics
  • 5-14 Consistency of granular soils at various relative densities
  • 5-15 Principal differences between standard and modified Proctor compaction tests
  • 5-16 Recommended minimum requirements for compaction of Embankment and subgrades
  • 5-17 Typical compacted densities and optimum moisture content for USCS soil types
  • 5-18 Typical compacted densities and optimum moisture contents for AASHTO soil types
  • 5-19 Grain size distribution of coarse particles
  • 5-20 Grain size distribution of fine particles
  • 5-21 Plasticity of fine-grained soils
  • 5-22 Characteristics of soils with different plasticity indices
  • 5-23 Swell potential of clays
  • 5-24 Estimation of swell potential
  • 5-25 Collapse potential of soils
  • 5-26 Other tests for aggregate quality and durability
  • 5-27 California Bearing Ratio
  • 5-28 Typical CBR values
  • 5-29 Stabilometer or R-Value
  • 5-30 Typical ranges for k1 and k2 coefficient in Equation 5.9
  • 5-31 Resilient modulus
  • 5-32 Average backcalculated to laboratory determined elastic modulus ratios
  • 5-33 Hierarchical input levels for unbound material stiffness in the NCHRP 1-37A Design Guide
  • 5-34 Correlations between resilient modulus and various material strength and index properties
  • 5-35 Default MR values for unbound granular and subgrade materials at unsoaked optimum moisture content and density conditions
  • 5-36 Recommended fractured slab design modulus values for Level 1 characterization
  • 5-37 Recommended fractured slab design modulus values for Level 3 characterization
  • 5-38 Typical Poisson's ratio values for geomaterials in pavements
  • 5-39 Typical values for k1 and k2 for use in Equation 5.17 for unbound base and subbase materials
  • 5-40 Granular base resilient modulus ESB values from AASHO Road Test
  • 5-41 Suggested bulk stress ? values for use in design of granular base layers
  • 5-42 Granular subbase resilient modulus ESB values from AASHO Road Test
  • 5-43 Suggested bulk stress ? values for use in design of granular subbase layers
  • 5-44 Suggested layer coefficients for existing flexible pavement layer materials
  • 5-45 Typical ranges of loss support, LS factors for various types of materials
  • 5-46 Suggested range for modulus of subgrade reaction for design
  • 5-47 Recommended friction factor values
  • 5-48 Typical values of base/slab friction coefficient recommended for CRCP design in the NCHRP 1-37A procedure
  • 5-49 Recommended mi values for modifying structural layer coefficients of untreated base and subbase materials in flexible pavements
  • 5-50 Recommended values of drainage coefficient Cd values for rigid pavement design
  • 5-51 Infiltration categories in the NCHRP 1-37A Design Guide
  • 5-52 Physical properties for unbound materials required for EICM calculations
  • 5-53 Options for estimating the SWCC parameters
  • 5-54 Options for determining the saturated hydraulic conductivity for unbound materials
  • 5-55 Saturated hydraulic conductivity
  • 5-56 Typical values of saturated hydraulic conductivity for soils
  • 5-57 Typical values of saturated hydraulic conductivity for highway materials
  • 5-58 Options for determining the dry thermal conductivity and heat capacity for unbound materials
  • 5-59 Typical values for thermal conductivity and heat capacity of unbound materials
  • 5-60 Summary of typical pavement parameter variability
  • 5-61 Resilient modulus versus CBR testing for fine grained subgrade soil
  • 6-01 Typical in-place unit material costs for use in example design problems
  • 6-02 Input parameters for 1993 AASHTO flexible pavement baseline design
  • 6-03 Input parameters for 1993 AASHTO rigid pavement baseline design
  • 6-04 Input parameters for NCHRP 1-37A flexible pavement baseline design
  • 6-05 AADTT distribution by truck class
  • 6-06 Hourly truck traffic distribution
  • 6-07 Truck axle load distributions: Percentage of axle loads by truck class
  • 6-08 Truck axle distribution
  • 6-09 Input parameters for NCHRP 1-37A rigid pavement baseline design
  • 6-10 Wheelbase spacing distribution
  • 6-11 Modified input parameters for NCHRP 1-37A flexible pavement design: soft subgrade scenario
  • 6-12 Trial cross sections for NCHRP 1-37A flexible pavement design: soft subgrade scenario
  • 6-13 Trial cross sections for NCHRP 1-37A rigid pavement design: soft subgrade scenario
  • 6-14 Modified input parameters for NCHRP 1-37A flexible pavement design: low quality base scenario
  • 6-15 Trial cross sections for NCHRP 1-37A flexible pavement design: low quality base scenario
  • 6-16 NCHRP 1-37A recommendations for assessing erosion potential of base material
  • 6-17 Trial cross sections for NCHRP 1-37A rigid pavement design: low quality base scenario
  • 6-18 Trial cross sections for NCHRP 1-37A rigid pavement design: poor drainage scenario
  • 6-19 Design pavement sections for 1993 AASHTO rigid pavement design: shallow bedrock effects
  • 6-20 Influence of bedrock depth on predicted total rutting: NCHRP 1-37A design method
  • 6-21 Trial cross sections for NCHRP 1-37A flexible pavement design: baseline conditions with shallow bedrock at 3 ft depth
  • 6-22 Influence of bedrock depth on predicted joint faulting: NCHRP 1-37A design methodology
  • 6-23 Trial cross sections for NCHRP 1-37A rigid pavement design: baseline conditions with shallow bedrock at 3 ft depth
  • 7-01 Moisture-related distresses in flexible (AC) pavements
  • 7-02 Moisture-related distresses in rigid (PCC) pavements
  • 7-03 Assessment of need for subsurface drainage in new or reconstructed pavements
  • 7-04 AASHTO definitions for pavement drainage recommended for use in both flexible and rigid pavement design
  • 7-05 Geotextile survivability requirements
  • 7-06 Level 1 recommendation for assessing erosion potential of base material
  • 7-07 Design Level 2 recommendations for assessing erosion potential of base material
  • 7-08 Design Level 3 recommendations for assessing erosion potential of base material description only
  • 7-09 Recommended asphalt stabilizer properties for asphalt-treated permeable base/subbase materials
  • 7-10 Recommended Portland cement stabilizer properties for cement treated permeable base/subbase materials
  • 7-11 Qualitative review of reinforcement application potential for paved permanent roads
  • 7-12 Frost susceptibility classification of soils
  • 7-13 Stabilization methods for pavements
  • 7-14 Transportation uses of geosynthetic materials
  • 7-15 Appropriate subgrade conditions for stabilization using geosynthetics
  • 7-16 Guide for selection of admixture stabilization method(s)
  • 7-17 Swell potential of soils
  • 7-18 Examples of the effects of lime stabilization on various soils
  • 7-19 Recommended gradations for bituminous stabilized subgrade materials
  • 7-20 Recommended gradations for bituminous-stabilized base and subbase materials
  • 7-21 Densities and approximate costs for various lightweight fill materials
  • 7-22 Ground improvement categories, functions, methods and applications
  • 7-23 Comparative costs of ground improvement methods
  • 8-01 Typical material properties measured for construction
  • 8-02 Field monitoring checklist
  • 8-03 Summary of design soil properties for example problem (pre-construction)
  • 8-04 Recommended field compaction equipment for different soils
  • 8-05 Geotechnical related post-construction problems in flexible pavements
  • 8-06 Geotechnical related post-construction problems in rigid pavements
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Updated: 04/07/2011
 

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