FINAL REPORT ON INDUCED TRENCH METHOD OF CULVERT INSTALLATION

THE INDUCED TRENCH (IMPERFECT TRENCH) METHOD OF CULVERT INSTALLATION IS USED TO REDUCE THE LOADS ON A CULVERT UNDER A HIGH FILL. ALTHOUGH THE METHOD HAS BEEN USED SUCCESSFULLY WITH CONCRETE PIPE UNDER SOME UNUSUALLY HIGH FILLS, THE MAGNITUDE OF THE REDUCTION IN LOAD ACHIEVED BY THE INDUCED TRENCH HAS NOT BEEN CLEARLY ESTABLISHED. THIS RESEARCH PROJECT WAS INITIATED TO EVALUATE THE SETTLEMENT RATIO AND TO COMPARE THE MEASURED LOADS ACTING ON THE CULVERT WITH THEORETICAL LOADS. SUCH AN EVALUATION WOULD BE USEFUL FOR ESTABLISHING DESIGN CRITERIA FOR THIS TYPE OF CONSTRUCTION. A DESCRIPTION IS INCLUDED OF THE CONSTRUCTION AND INSTRUMENTATION OF A 48-INCH REINFORCED CONCRETE PIPE CULVERT INSTALLED BY THE INDUCED TRENCH METHOD. SETTLEMENT DATA WERE COLLECTED AND ANALYZED TO DETERMINE THE SETTLEMENT RATIO FOR THIS TYPE OF INSTALLATION. IN ADDITION, THE PRESURES ACTING AT THE TOP AND SIDES OF THE PIPE WERE MEASURED AND COMPARED WITH THEORETICAL LOADS DETERMINED BY MARSTON'S THEORY OF LOADS ON UNDERGROUND CONDUITS. THE RESULTS INDICATE THAT THE RANGE OF EMPIRICAL VALUES THAT HAVE BEEN RECOMMENDED FOR THE SETTLEMENT RATIO FOR THE INDICATE THAT THE RANGE OF EMPIRICAL VALUES THAT HAVE BEEN RECOMMENDED FOR THE SETTLEMENT RATIO FOR THE INDUCED TRENCH IS REASONABLE FOR THIS TYPE OF CULVERT UNDER 30 FEET OF FILL. A COMPARISON OF THE MEASURED LOADS ACTING ON THE CULVERT WITH THEORETICAL LOADS INDICATES THAT THE LOAD THEORY IS SOMEWHAT CONSERVATIVE. /FHWA/

  • Supplemental Notes:
    • Contract No IHR-77
  • Corporate Authors:

    Illinois Department of Transportation

    2300 S. Dirksen Parkway
    Springfield, IL  United States  62764
  • Authors:
    • TAYLOR, R K
  • Publication Date: 1971-11

Media Info

  • Pagination: 52 p.
  • Serial:
    • Issue Number: 38

Subject/Index Terms

Filing Info

  • Accession Number: 00214534
  • Record Type: Publication
  • Source Agency: Illinois Department of Transportation
  • Files: TRIS
  • Created Date: Apr 23 1973 12:00AM