SELECTION OF MATERIALS FOR SUB-SURFACE DRAINS

THE PART PLAYED BY THE VARIOUS COMPONENTS OF A SUB-SURFACE DRAIN IN ACHIEVING ADEQUATE PREMEABILITY AND IN PREVENTING DRAIN CLOGGING BY SILT ARE DISCUSSED. PRESENT CRITERIA FOR THE GRADING LIMITS OF THE BACKFILL AND THE POROSITY OF THE PIPES IN A DRAIN ARE REVIEWED, AND CONSLUSIONS ARE REACHED AS FOLLOWS:- (1) THE MOST RELIABLE CRITERIA FOR BACKFILL IN SANDS AND GRAVELS ARE THOSE OF THE UNITED STATES WATERWAYS EXPERIMENT STATION, WHICH ARE BASED ON RATIOS OF THE PARTICLE SIZES OF THE BACKFILL AND THE SURROUNDING SOIL; (2) FOR DRAINS IN SILTS AND CLAYS, B.S.882, ZONE 2 CONCRETE SAND IS RECOMMENDED AS A BACKFILL; (3) MAXIMUM PIPE HOLE SIZES SHOULD BE EQUAL TO THE 85% SIZE OF THE BACKFILL FOR CIRCULAR HOLES, AND THE WIDTHS OF SLOTS SHOULD BE SLIGHTLY LESS. MORE EXPERIMENTS ARE NEEDED TO CONFIRM THE FILTER DESIGN CHART PROPOSED BY THE WATERWAYS EXPERIMENT STATION. FURTHER RESEARCH IS SUGGESTED TO DETERMINE THE NUMBER AND SIZE OF HOLES REQUIRED IN A PIPE, PIPE ROUGHNESS VALUES, AND ALSO THE EFFECT OF COMPACTION ON THE ALLOWABLE HOLE SIZES IN PIPES. /RRL(A)/

  • Supplemental Notes:
    • Rrl Rept Lr 346, 38 PP, 15 FIG, 1 TAB, 21 REF
  • Corporate Authors:

    Road Research Laboratory /UK

    ,    
  • Authors:
    • Spalding, R
  • Publication Date: 1970

Subject/Index Terms

Filing Info

  • Accession Number: 00237638
  • Record Type: Publication
  • Source Agency: Road Research Laboratory /UK
  • Files: TRIS, ATRI
  • Created Date: Jul 2 1971 12:00AM