Procedures for Establishing Geotechnical Design Parameters from Two Data Sources

The Missouri Department of Transportation (MoDOT) recently adopted new provisions for geotechnical design that require that the mean value and the coefficient of variation (COV) for the mean value of design parameters be established in order to determine appropriate values for resistance factors to be used for design of specific projects. Current guidelines include provisions to establish appropriate values for the mean and COV of the mean for relevant design parameters based on lab or field measurements made for a specific project. This report describes procedures developed to establish geotechnical design parameters and their variability when there are two sources of data that can be used to estimate values for the design parameter. The proposed procedures include methods for establishing the mean and COV of the mean for a design parameter from “surrogate” measurements that can be related to the design parameter of interest as well as procedures for establishing the mean and COV for a design parameter from combined direct and surrogate measurements. The procedures are demonstrated through application to direct measurements of uniaxial compressive strength and surrogate Standard Penetration Test (SPT) measurements in Missouri shales. Results of analyses presented demonstrate that use of combined direct and surrogate measurements produces smaller values of COV when compared to use of direct measurements alone but that the magnitude of the reduction in COV depends on the number of direct and surrogate measurements available and on the variability and uncertainty present in the relation between the surrogate measurements and the design parameter of interest. Results of the analyses also show that SPT measurements are generally a poor predictor of uniaxial compressive strength and drilled shaft capacity in shale when compared to direct measurements of uniaxial compressive strength.

• Record URL:
  • https://spexternal.modot.mo.gov/sites/cm/CORDT/cmr14-002.pdf
• 
• Corporate Authors:

  University of Missouri, Columbia

  Department of Civil Engineering
  E 2509 Lafferre Hall
  Columiba, MO  United States  65211

  Missouri Department of Transportation

  Research, Development and Technology
  P.O. Box 270
  Jefferson City, MO  United States  65102
• Authors:
  • Loehr, J Erik
  • Boeckmann, Andrew Z
  • Speckman, Paul L
  • Ding, Dan
• Publication Date: 2013-7

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Research Report
• Features: Figures; References; Tables;
• Pagination: 25p

Subject/Index Terms

• TRT Terms: Compressive strength; Design standards; Geotechnical engineering; Load and resistance factor design; Mean (Statistics); Shale; Shear strength; Soil penetration test
• Uncontrolled Terms: Coefficient of variation
• Subject Areas: Design; Geotechnology; Highways; I20: Design and Planning of Transport Infrastructure; I42: Soil Mechanics;

Filing Info

• Accession Number: 01493433
• Record Type: Publication
• Report/Paper Numbers: cmr 14-002
• Contract Numbers: TRyy1204
• Files: TRIS, ATRI, STATEDOT
• Created Date: Sep 20 2013 9:54AM