THE INTERPRETATION OF REPEATED LOAD PARAMETERS FOR A GLACIAL SUBGRADE FROM SOIL PROPERTIES --PROCEEDINGS OF THE FIFTH INTERNATIONAL CONFERENCE ON THE STRUCTURAL DESIGN OF ASPHALT PAVEMENTS HELD DEFLT UNIVERSITY OF TECHNOLOGY, AUGUST 23-26 1982. VOL 1 AND 2. -- NETHERLANDS

This paper presents the results of an investigation to establish simple methods for estimating the resilient and permanent deformation parameters of a till subgrade from standard laboratory tests. The subgrade deformation parameters necessary for the satisfactory design of a flexible pavement depend on the water content and dry density of the subgrade soil and on the applied stresses and other factors. A programme of repeated load triaxial tests has been carried out to investigate the influence of these variables on the required parameters such as resilient modulus, Poisson's ratio and creep compliance. The experimental data from the repeated loading tests has been used to prepare charts relating the resilient modulus and creep compliance to the dry density and water content. These charts show that the creep compliance is very sensitive to change in water content and, except for samples with high dry densities, the resilient modulus is more sensitive to changes in water content than dry density and decreases as the water content increases. Repeated load tests were also carried out in a laboratory pavement simulator. The deformation parameters interpreted from the pavement deflections measured in these tests are in close agreement with the values predicted by the charts from the repeated load triaxial testing programme for the in-situ dry density and water content. The effect of variations in the modulus of resilience and creep compliance of the subgrade on the performance and design life of a pavement was investigated. This was carried out by examining the experimental results and the results of a parametric analysis using a finite element program. The results of the parametric analysis show that changes in the subgrade properties have a greater effect on rutting of the pavement than on the fatigue life of the asphalt layer.(a) for the covering abstract of the conference see IRRD 815640.

• Corporate Authors:

  INTERNAT EXE COMM. STUDY CENTRE FOR ROAD CONSTR.

  PO BOX 1062
  Ba Arnhem,   Netherlands 
• Authors:
  • Kirwan, R W
  • FARRELL, E R
  • Hartford, DND
  • Orr, TLL
• Publication Date: 1982

Language

• English

Media Info

• Pagination: p. 768-79
• Serial:
  • Publication of: INTERNAT EXE COMM. STUDY CENTRE FOR ROAD CONSTR.
  • Publisher: INTERNAT EXE COMM. STUDY CENTRE FOR ROAD CONSTR.

Subject/Index Terms

• TRT Terms: Charts; Conferences; Creep; Deflection; Deformation; Density; Durability; Fatigue (Mechanics); Flexible pavements; Glacial soils; Modulus of elasticity; Moisture content; Pavement design; Poisson distributions; Poisson ratio; Repeated loads; Resilience (Materials); Rutting; Soils; Subgrade (Pavements); Till
• Uncontrolled Terms: Till (Soil)
• Subject Areas: Geotechnology; Highways; Pavements;

Filing Info

• Accession Number: 00483016
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: ITRD, TRIS
• Created Date: May 31 1989 12:00AM