Home Skip to main content

MPC Research Reports
Report Details

Title:Selection of Subgrade Modulus for Pavement Overlay Design Procedures
Authors:Khaled Ksaibati, Michael Whelan, James Burczyk, and Michael Farrar
University:University of Wyoming
Publication Date:Dec 1994
Report #:MPC-94-34
Project #:MPC-046
TRID #:00674272
Keywords:backcalculation, bituminous overlays, coefficient of subgrade reaction, cohesive soils, deviatoric stress, future, laboratory tests, modulus of resilience, overlays (pavements), research, thickness


This report describes a study jointly conducted by the University of Wyoming and the Wyoming Department of Transportation to better understand how selecting an Mr value influences the thickness of an asphalt overlay pavement. The objectives of this study were to: 1) investigate the importance of several fundamental soil properties (water content, plasticity index, liquid limit, group index) in selecting a design subgrade resilient modulus value for cohesive soils; 2) define the actual relationship (correction factor) between back-calculated and laboratory based MR values for typical cohesive subgrade soils in Wyoming; 3) compare actual subgrade field deviator stresses to the deviator stress assumed in determining a design MR value from laboratory testing; and 4) determine the effect of selecting a MR value on the design overlay thickness for typical pavement sections in Wyoming.

NDSU Dept 2880P.O. Box 6050Fargo, ND 58108-6050