Field Study of Integral Backwall with Elastic Inclusion

Jointless construction is considered an effective design option to reduce bridge maintenance costs and resist seismic loads. Although these attributes make the integral bridge an increasingly popular choice, soil-structure interaction issues unique to this type of design remain unresolved. Of particular concern is the excessive settlement of approach embankments, resulting from the repetitive, thermally induced cyclic movements of the superstructure. In many cases, rectifying this condition can be expensive because the integral bridge approach slab (if provided) cannot be overlaid with pavement. To address this soil-structure interaction problem, the Virginia Department of Transportation conducted a study designed to test the feasibility of using elastic inclusion at the integral backwall. The design was completed in mid-1997, and the bridge was opened to traffic in October 1999. The bridge was constructed with elasticized expanded polystyrene (EPS) attached to the backwall. The structure has been monitored continuously for 5 years. Significantly attenuated lateral earth pressures have been recorded at the backwall, and the settlement of the approach fill has been tolerable. Field data indicate that the elasticized EPS layer has been functioning effectively in allowing the superstructure to interact with the adjoining select backfill material. The use of elasticized EPS in conjunction with a well-compacted granular backfill offers a cost-effective way of minimizing settlements at bridge approaches.

• Record URL:
  • http://www.virginiadot.org/vtrc/main/online_reports/pdf/05-r28.pdf
• 
• Record URL:
  • https://rosap.ntl.bts.gov/view/dot/19683
• Corporate Authors:

  Virginia Transportation Research Council

  530 Edgemont Road
  Charlottesville, VA  United States  22903

  Virginia Department of Transportation

  1401 East Broad Street
  Richmond, VA  United States  23219

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Hoppe, Edward J
• Publication Date: 2005-4

Language

• English

Media Info

• Media Type: Print
• Edition: Final Report
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 36p

Subject/Index Terms

• TRT Terms: Backfill soils; Bridge approaches; Bridge design; Cost effectiveness; Embankments; Granular materials; Jointless bridges; Soil structure interaction; Structural settlement; Styrenes
• Uncontrolled Terms: Backwall; Elastic inclusion; Field data; Integral bridges; Lateral earth pressures
• Subject Areas: Bridges and other structures; Design; Geotechnology; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 01000460
• Record Type: Publication
• Report/Paper Numbers: FHWA/VTRC 05-R28
• Contract Numbers: 54168
• Files: NTL, TRIS, USDOT, STATEDOT
• Created Date: May 27 2005 4:21PM