PRESSURE DISTRIBUTION AROUND A METAL PIPE UNDER DEEP COVER

A multi-plate corrugated steel culvert was built on Nease Creek in southeast Ohio under SR 224 and US 33. The culvert was 252 in. in diameter and 439 ft long. The culvert was covered with up to 75 ft of backfill consisting of Ohio Department of Transportation (ODOT) #304 crushed limestone and local silty clay soil. The steel plates were 0.375 in. thick and had a 6 in. by 2 in. corrugation profile. The culvert design used slotted blot joints to relieve stress caused by backfill. Earth pressure cells were mounted around the culvert to measure vertical soil pressure at the crown and at the springline and horizontal soil pressure at the springline underneath centerline and shoulder of the road. The horizontal and vertical diameters of the culvert were measured during and after construction. CANDE-89 was used to generate a finite element model of the culvert during and after construction. Vertical soil pressure under the road shoulder after construction was 35.4 psi on the crown and 20.1 psi at the springline; lateral soil pressure at the springline was 27.5 psi on the west side of the culvert and 14.3 psi on the east side. Soil pressure on the crown under the centerline was 25.8 psi and the lateral pressure on the east side was 23.5 psi; the other pressure sensors malfunctioned. The culvert showed peaking behavior; when backfill reached the top of the culvert, the vertical diameter had increased by 2.15 in. (0.85%) and the horizontal diameter had decreased by 1.97 in. (-0.78%). After construction was completed the vertical diameter had decreased by 8.2 in. (-3.4%) and the horizontal diameter had increased by 6.6 in. (2.6%). The interface elements in CANDE would not allow the computation to converge, so full bonding between soil and culvert was assumed. CANDE was unable to predict the peaking behavior seen during construction, predicting vertical diameter decreasing by 2.49 in. (-0.99%) and horizontal diameter increasing by 2.4 in. (0.95%). Final deflections computed by CANDE agreed somewhat better with vertical diameter decreasing by 5.79 in. (-2.3%) to 7.58 in. (-3.0%) and horizontal diameter increasing by 2.96 in. (1.1%) to 3.36 in. (1.3%). CANDE also overpredicted soil pressures by a factor of 2-3, though the fit was improved by assuming some joint slippage in the model. The field measured soil pressures indicated joint slipping occurring when backfill height ranged from about 10 ft to 50-60 ft.

• Corporate Authors:

  Ohio University, Athens

  Ohio Research Institute for Transportation and the Environment
  141 Stocker Engineering and Technology Center
  Athens, OH  United States  45701-2979

  Ohio Department of Transportation

  Office of Research and Development
  1980 West Broad Street
  Columbus, OH  United States  43223

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Sargand, S M
  • Moreland, A
• Publication Date: 2004-12

Language

• English

Media Info

• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 86 p.

Subject/Index Terms

• TRT Terms: Backfill soils; Corrugated metal culverts; Corrugated steel; Crushed limestone; Depth; Earth pressure; Finite element method; Mathematical prediction; Measurement; Metal pipe; Silty clays; Soil structure interaction
• Identifier Terms: CANDE (Computer program)
• Geographic Terms: Ohio
• Subject Areas: Data and Information Technology; Geotechnology; Highways; I42: Soil Mechanics;

Filing Info

• Accession Number: 00987672
• Record Type: Publication
• Report/Paper Numbers: FHWA/OH-2004/019,, Final Report
• Contract Numbers: State Job No. 14792(0)
• Files: TRIS, USDOT, STATEDOT
• Created Date: Mar 10 2005 12:00AM