SEISMIC RESPONSE OF TIEBACK RATAINING WALLS - PHASE I. FINAL REPORT

The current design practice used by WSDOT for the design of permanent tieback walls is to assume that the static design of a tieback wall retaining clayey soils provides an adequate reserve of strength to prevent failure during seismic loading. This design procedure is based largely on the assumption that the soil and the wall move together during ground shaking and that significant dynamic loads are not produced. For tieback walls retaining sandy soils, it is assumed that dynamic loads are produced. Mononobe-Okabe dynamic soil pressures are added to the static design pressure to account for the dynamic load. The validity of these assumptions and the resultant design practices is evaluated in this study. A pilot numerical study was conducted on a forty foot high wall with three levels of tiebacks using the program FLUSH. It was found that the wall and the soil tend to move in-phase and only negligible dynamic tie forces are generated. However, the soil above and below the excavation level tends to move out-of-phase, leading to significant dynamic pressures and bending moments in the wall and near the excavation level. It appears that in some cases, tieback walls with an adequate static safety factor may suffer significant damage or fail during seismic loading and that the use of Mononobe-Okabe dynamic prssures may be conservative.

• Record URL:
  • http://www.wsdot.wa.gov/research/reports/fullreports/138.1.pdf
• 
• Corporate Authors:

  Washington State University, Pullman

  Washington State Transportation Center
  Pullman, WA  United States  99164

  Washington State Department of Transportation

  Transportation Building, 310 Maple Park Avenue SE, P.O. Box 47300
  Olympia, WA  United States  98504-7300

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • FRAGASZY, R J
  • Denby, G
  • Higgins, J D
  • ALI, N
• Publication Date: 1987-12

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: 75 p.

Subject/Index Terms

• TRT Terms: Bending moments; Clay soils; Computer programs; Design methods; Dynamic loads; Earth pressure; Failure; Retaining walls; Safety factors; Sandy soils; Seismicity; Static pressure; Structural design; Tiebacks
• Uncontrolled Terms: Seismic response
• Subject Areas: Bridges and other structures; Design; Highways; Safety and Human Factors; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00467789
• Record Type: Publication
• Report/Paper Numbers: WA-RD-138.1
• Contract Numbers: Y 3400 Task 11 #664
• Files: TRIS, USDOT, STATEDOT
• Created Date: Mar 31 1988 12:00AM