VOID DEVELOPMENT UNDER BRIDGE APPROACHES. FINAL REPORT

The development of voids under approach slabs to bridges can lead to distress of the approach system resulting in decreased life expectancy, increased maintenance costs for repair and stabilization, and rider discomfort due to "bumps" resulting from grade differences in the approach system. The mechanisms involved in the development of the void generally are attributed to settlement problems of the foundation and embankment soils. A special backfill is often used under approach slabs to reduce such settlement problems. In recent years the South Dakota Department of Transportation (SDDOT) has observed increasing subsidence problems associated with the special backfill. The objectives of the research were to estimate the number of bridges affected by bridge end backfill settlement, to determine the cause and significance of bridge end settlement, to evaluate the cost-effectiveness of the current bridge end backfill design, and to develop recommendations for the maintenance of existing bridge end backfill systems and for design improvements for future systems. The work included an extensive survey of some 140 bridges across South Dakota to determine and document the extent of the problem; a review of previous work related to bridge approach settlement; a survey of state transportation departments concerning approach system and bridge abutment problems and design methodology; and development of a field scale model of an integral abutment bridge/approach system to isolate and determine the mechanisms controlling backfill subsidence.

• Corporate Authors:

  South Dakota State University, Brookings

  Department of Civil Engineering, 122 Crothers Engineering Hall
  Brookings, SD  United States  57007-0495

  South Dakota Department of Transportation

  Office of Research
  700 East Broadway Avenue
  Pierre, SD  United States  57501-2586

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Schaefer, V R
  • Koch, J C
• Publication Date: 1992-11-30

Language

• English

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: 257 p.

Subject/Index Terms

• TRT Terms: Backfilling; Bridge approaches; Data collection; Design; Embankments; Foundation soils; Maintenance; Recommendations; Scale models; Settlement (Structures); State departments of transportation; Subsidence (Geology); Surveys; Void ratios
• Uncontrolled Terms: Voids
• Old TRIS Terms: Backfills
• Subject Areas: Bridges and other structures; Design; Geotechnology; Highways; Maintenance and Preservation; Research; I42: Soil Mechanics;

Filing Info

• Accession Number: 00634382
• Record Type: Publication
• Report/Paper Numbers: SD90-03-F
• Contract Numbers: 303417
• Files: TRIS, USDOT, STATEDOT
• Created Date: Jul 26 1993 12:00AM