Prediction of Subgrade Resilient Modulus Using Genetic Algorithm and Curve Shifting Methodology as An Alternative to Nonlinear Constitutive Models

This paper demonstrates the applicability of the genetic algorithm and curve shifting methodology to estimate resilient modulus at various stress states for subgrade soils using the results of triaxial resilient modulus tests. This innovative methodology is proposed as an alternative to conventional nonlinear constitutive relationships. Using the genetic algorithm, laboratory curves for different deviator stress levels at different confining pressures are horizontally shifted to form a final gamma distribution curve which can represent the stress-strain behavior of subgrade soils. Resilient modulus values for a given stress state can be estimated based on this curve and another gamma function which represents the variation of shift values for different confining stresses. To compare the effectiveness of these two approaches, coefficients for the Uzan constitutive model are also determined for each laboratory test and compared with the approach described in this paper. Critical stresses determined by using KENPAVE for a representative pavement section are integrated with both the Uzan and the curve shifting models to determine resilient modulus values for different subgrade soil types. Predicted resilient modulus values from each approach are separately compared with Artificial Neural Network (ANN) model predictions to compare their efficiency and reliability in terms of resilient response prediction. Results of the analysis indicated that curve shifting methodology gives superior estimates with a coefficient of determination 14% higher than the Uzan model predictions when the results are compared with the ANN model outputs. Thus, although it is not a constitutive model, use of the genetic algorithm and curve shifting methodology is proposed as a promising technique for the evaluation of subgrade soils’ stress-strain dependency.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Coleri, Erdem
  • Guler, Murat
  • Gungor, A. Gurkan
  • Harvey, John T
• Conference:
  • Transportation Research Board 88th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2009-1-11 to 2009-1-15
• Date: 2009

Language

• English

Media Info

• Media Type: DVD
• Features: Figures; References; Tables;
• Pagination: 23p
• Monograph Title: TRB 88th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Curves (Geometry); Deformation curve; Genetic algorithms; Neural networks; Soil mechanics; Subgrade (Pavements)
• Uncontrolled Terms: Resilient modulus
• Subject Areas: Geotechnology; Highways; I42: Soil Mechanics;

Filing Info

• Accession Number: 01122397
• Record Type: Publication
• Report/Paper Numbers: 09-2375
• Files: TRIS, TRB
• Created Date: Feb 19 2009 2:43PM