This paper summarizes the work session on subdrainage held at the 1973 Federal Highway Administration workshop on Water in Pavements in Des Moines, Iowa. It was decided to include any system draining soil water in the discussion, while at the same time excluding vertical sand drains, well-point systems, pilot trenches, or similar installations. Pavement drainage is designed to intercept seepage and to bleed off water from precipitation. States use underdrains to implement pavement system drainage, to stabilize backslopes, and as toe drains for embankments that also impound water. Six-inch (15-cm) perforated metal pipe is the most widely used type of pipe in underdrains. Other materials used include concrete, polyethylene, and filter cloth with rock. Nominal depths of underdrains appear to be about 4 ft (1.2 m), but exceptions are made to get below frost, to meet pavement base or subbase layers, and to get below shallow seepage zones. Concrete sand is used most often for backfill of drainage structures. Filter cloth, while still a comparative newcomer, appears to be coming into wide usage. It was agreed that mineral build-up, damage from mowers or other equipment, silting, and rodent nests all have to be recognized as maintenance program problems. In some states, soils personnel locate drains on plans; while in others, the soils people show a general area and need, with designers placing drains on the plans.

  • Supplemental Notes:
    • This paper was presented at a 1973 workshop on Water in Pavements sponsored by the Federal Highway Administration, held in Des Moines, Iowa.
  • Corporate Authors:

    Federal Highway Administration

    Office of Research, Development, Engineering and Highway Operations, 1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Laughter, C N
  • Conference:
  • Publication Date: 1973


  • English

Media Info

  • Pagination: p. 257-260

Subject/Index Terms

Filing Info

  • Accession Number: 00792266
  • Record Type: Publication
  • Files: TRIS, USDOT
  • Created Date: May 6 2000 12:00AM