CONSIDERATIONS OF SATURATED SOIL CONDITIONS IN BACKCALCULATION OF PAVEMENT LAYER MODULI

The need to account for stiff underlying soil and rock layers has long been recognized in pavement layer modulus backcalculation. Recently, it has been suggested by other researchers that there is a need to separately characterize and incorporate materials below the water table when backcalculating moduli. This discussion is continued by presenting means for determining the depth to the water table and how to assign an appropriate modulus to this material. Results compare the depths to the water table determined by a reflection survey with those obtained by using regression equations developed for deflection testing. It was found that in the case of asphalt concrete over granular base materials, both approaches produced depths close to water table depths in open standpipes. However, there was considerable discrepancy between the depths when the testing was performed on a full-depth asphalt pavement. An appropriate modulus for soil beneath the water table could be determined by minimizing the error between measured and theoretical deflections. It was found that over a time period from fall to spring both the depth to the water table and the modulus of this material did not remain constant. As a result it was concluded that there is a need to determine the depth to the water table and the modulus of the material below the water table each time that deflection testing and deflection analysis are performed.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1995/1473/1473-008.pdf
• Record URL:
  • https://scholar.google.com/scholar_lookup?title=CONSIDERATIONS+OF+SATURATED+SOIL+CONDITIONS+IN+BACKCALCULATION+OF+PAVEMENT+LAYER+MODULI&author=D.+Newcomb&author=D.+Van+Deusen&author=Y.+Jiang&author=J.+Mahoney&publication_year=1995
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  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309061121
• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1473, Strength and Deformation Characteristics of Pavement Sections and Pavement Rehabilitation. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Authors:
  • Newcomb, David E
  • Van Deusen, David A
  • Jiang, Yan
  • Mahoney, Joe P.
• Publication Date: 1995

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 63-71
• Monograph Title: Strength and deformation characteristics of pavement sections and pavement rehabilitation
• Serial:
  • Transportation Research Record
  • Issue Number: 1473
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Asphalt concrete; Asphalt pavements; Backcalculation; Depth; Full-depth asphalt pavements; Granular bases; Modulus of elasticity; Pavement layers; Saturated soils; Water table
• Subject Areas: Data and Information Technology; Design; Geotechnology; Highways; Hydraulics and Hydrology; Pavements; I22: Design of Pavements, Railways and Guideways;

Filing Info

• Accession Number: 00682840
• Record Type: Publication
• ISBN: 0309061121
• Files: TRIS, TRB, ATRI
• Created Date: Aug 24 1995 12:00AM