Cone Penetration TestDesign Guide forState Geotechnical EngineersAuthor: David SaftnerReport Number: 2018-32Date Published: November 2018Minnesota Department of TransportationResearch Services & Library395 John Ireland Boulevard, MS 330St. Paul, Minnesota 55155-1899mndot.gov/research
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Technical Report Documentation Page1. Report No.2.3. Recipients Accession No.MN/RC 2018-324. Title and Subtitle5. Report DateCone Penetration Test Design Guide for State GeotechnicalEngineersNovember 20187. Author(s)8. Performing Organization Report No.6.Ryan Dagger, David Saftner, and Paul Mayne9. Performing Organization Name and Address10. Project/Task/Work Unit No.Department of Civil EngineeringUniversity of Minnesota Duluth1405 University DriveDuluth, MN 55812CTS#201702212. Sponsoring Organization Name and Address13. Type of Report and Period CoveredMinnesota Department of TransportationResearch Services & Library395 John Ireland Boulevard, MS 330St. Paul, Minnesota 55155-1899Final Report11. Contract (C) or Grant (G) No.(C) 99008 (WO) 24914. Sponsoring Agency Code15. Supplementary .pdf16. Abstract (Limit: 250 words)The objectives of this project are focused on a new cone penetration testing (CPT) geotechnical designmanual for highway and transportation applications based on recent research and innovation covering theperiod from 2000 to 2018. A step-by-step procedure is outlined on how to use CPT data in the analysis anddesign of common geotechnical tasks.Previous manuals are either very outdated with information from 1970-1996, or not appropriately targeted totransportation works. This design document introduces modern and recent advancements in CPT researchnot otherwise captured in legacy manuals from the 1990’s and earlier. Examples and case studies areprovided for each topic interpreted using CPT measures.In the manual, a step-by-step procedure is outlined on how to use CPT data in analysis and design for typicalgeotechnical practices. These topics, which are applicable both to state highways and local roads, includebridge foundations (including shallow footings and deep foundations) and soil characterization (includingdetermination of standard soil engineering properties).17. Document Analysis/Descriptors18. Availability StatementCone penetrometers, Geographic information systems, Soils byproperties, Bridge foundations, Soil mechanicsNo restrictions. Document available from:National Technical Information Services,Alexandria, Virginia 2231219. Security Class (this report)20. Security Class (this page)21. No. of PagesUnclassifiedUnclassified22522. Price
CONE PENETRATION TEST DESIGN GUIDE FOR STATEGEOTECHNICAL ENGINEERSPrepared by:Ryan DaggerDavid SaftnerDepartment of Civil EngineeringUniversity of Minnesota DuluthPaul W. MayneSchool of Civil & Environmental EngineeringGeorgia Institute of Technology, AtlantaNovember 2018Published by:Minnesota Department of TransportationResearch Services & Library395 John Ireland Boulevard, MS 330St. Paul, Minnesota 55155-1899This report represents the results of research conducted by the authors and does not necessarily represent the views or policiesof the Minnesota Department of Transportation, the University of Minnesota Duluth, or the Georgia Institute of Technology.This report does not contain a standard or specified technique.The authors, the Minnesota Department of Transportation, the University of Minnesota Duluth, and the Georgia Institute ofTechnology do not endorse products or manufacturers. Trade or manufacturers’ names appear herein solely because they areconsidered essential to this report because they are considered essential to this report.
TABLE OF CONTENTSCHAPTER 1: INTRODUCTION.1CHAPTER 2: DIRECT CPT METHOD FOR SOIL CHARACTERIZATION .42.1 Introduction. 42.2 Soil Unit Weight. 62.3 CPT Material Index. 72.3.1 Step 1. Normalized Sleeve Friction . 72.3.2 Step 2. Iteration. 82.4 Soil Behavior Type (SBT) . 82.4.1 Step 1. 82.4.2 Step 2. 92.5 Effective Stress Friction Angle . 92.6 Stress History . 102.7 Lateral Stress Coefficient . 112.8 Undrained Shear Strength . 122.9 Ground Stiffness and Soil Moduli . 122.10 Coefficient of Consolidation . 132.11 Hydraulic Conductivity. 142.12 Example Problems . 152.12.1 Example 1: Direct CPT Methods for Geoparameters on Sands . 152.12.2 Example 2: Direct CPT Methods for Geoparameters on Clay . 33CHAPTER 3: DIRECT CPT METHOD FOR SHALLOW FOUNDATIONS .563.1 Procedure . 563.1.1 Step 1. Estimating Footing Dimensions. 573.1.2 Step 2. Soil Characterization . 58
3.1.3 Step 2a. Foundation soil formation parameter. 593.1.4 Step 3. Soil elastic modulus and Poisson’s ratio . 603.1.5 Step 4. Net cone tip resistance . 603.1.6 Step 5. Bearing capacity of the soil . 613.1.7 Step 6. Settlement. 613.1.8 Step 7. Final Check . 613.2 Example Problems . 623.2.1 Example 3: Direct CPT Method on Sands . 62CHAPTER 4: DIRECT CPT METHOD FOR DEEP FOUNDATIONS .704.1 Introduction. 704.2 Modified UniCone Method. 724.2.1 Step 1. 724.2.2 Step 2. 724.2.3 Step 3. 734.2.4 Step 4. 734.3 Axial Pile Displacements . 734.4 Example Problems . 744.4.1 Example 5: Direct CPT Methods Axial Pile Capacity. 74REFERENCES .87APPENDIX AAPPENDIX BAPPENDIX C
LIST OF FIGURESFigure 1. Geoparameters determined from CPT. . 1Figure 2. Conventional method for shallow foundation design compared to direct CPT method. 2Figure 3. Direct CPT evaluation of axial pile capacity. . 3Figure 4. Soil unit weight from CPT sleeve friction. . 6Figure 5. Approximate “rules of thumb” method using CPT sounding from Wakota Bridge, MN. . 7Figure 6. SBT zones using CPT Ic. . 9Figure 7. Yield stress exponent compared to CPT material index. . 11Figure 8. k vs. dissipation time for 50% consolidation (Mayne 2017). . 15Figure 9. CPT data from Benton County, Minnesota for example problem 1. . 16Figure 10. Soil layers using “rules of thumb.”. 17Figure 11. Soil layer 1 using SBT method. . 23Figure 12. Soil layer 2 using SBT method. . 24Figure 13. Soil layer 3 using SBT method. . 25Figure 14. Soil layer 4 using SBT method. . 26Figure 15. CPT data from Minnesota for example problem 2. . 34Figure 16. Soil layers using “rules of thumb.”. 36Figure 17. Soil layer 1 using SBT method. . 42Figure 18. Soil layer 2 using SBT method. . 43Figure 19. Soil layer 3 using SBT method. 44Figure 20. Soil layer 4 using SBT method. . 45Figure 21. Dissipation, t50 data. . 53Figure 22. Direct CPT method for shallow foundations. 56Figure 23. Direct CPT method introduction. . 58Figure 24. Differentiation of porewater pressure measurement locations (Lunne et al., 1997). . 58
Figure 25. Foundation soil formation parameter hs versus CPT material index, Ic (Mayne 2017). . 60Figure 26. Diagram of footing profiles for Example 3. 62Figure 27. CPT data from Northern Minnesota. . 63Figure 28. Schematic of foundation design associated with CPT data. . 64Figure 29. Soil type for example problem 3. 67Figure 30. Direct CPT evaluat