Increased demand in the passenger and freight services during recent years dictated that the Portland International Airport be expanded. Economics dictated that an extension to an existing runway was the solution. The Portland International Airport is located on the flood plain deposits of the Columbia River. These deposits range, generally, from coarse sands downward to fine sands and sensitive silts. These natural deposits have in some areas been overlain by dredged material from the adjacent Columbia River. The problem soils encountered were sensitive silts and very fine silty sands which would consolidate and liquify when distrubed. Problems with these soils were amplified because of a high water table in the area. The design considerations for the runway and taxiway construction on these problem soils involved a total structural pavement section nearly 6 feet in thickness. The runway surface was a 4-inch layer of asphaltic concrete over 30 inches of LCPF stabilized base, all placed on a minimum of 36 inches of compacted sand. The intials LCPF stand for Lime, Cement, Pozzolan and Filler. Solutions of embankment construction problems included placing of surcharges, to consolidate soft areas, over-excavation of bad subgrade material and compaction of the sand portion of the structural pavement section. In many areas the problems with the fine silty soils were so severe that those areas were completely removed and replaced with clean Columbia River sand or crushed rock. The field density testing on the sand subgrade, LCPF stabilized base and asphalt surfacing material was conducted with nuclear density gauges. However, sand cone density tests were made and cores were extracted and tested in the laboratory. With respect to the construction involved, including quality control, field inspection, and field engineering, the runway construction at Portland International Airport was a milestone for the Port and for those that participated in it.

  • Supplemental Notes:
    • The Symposium held on April 2-4 1975 at Moscow, Idaho, was jointly sponsored by Idaho Transportation Department University of Idaho, Moscow; Idaho State University Pocatello; and Boise State University.
  • Corporate Authors:

    Idaho Department of Highways

    P.O Box 7129
    Boise, ID  United States  83707
  • Authors:
    • Sennett, R B
  • Publication Date: 1975-4

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  • Accession Number: 00127660
  • Record Type: Publication
  • Created Date: Mar 10 2002 12:00AM