Development of ARS Curve for a Long Multi-Span Bridge at a Liquefiable (Type F) Site

This paper presents a practical approach to develop a site-specific design acceleration response spectral (ARS) curve for a soil profile Type F site due to liquefaction. A bridge structure was proposed as a connector separation consisting of a 15-span, cast-in-place, prestressed box girder structure supported on Abutment 1, Bents 2 through 15, and Abutment 16. The bridge will be approximately 3,911 feet long with a constant width of 41.8 feet. The bridge seismic design criteria require using an Upper Level Earthquake (ULE) having a 975-year average return period probabilistic response spectrum or Caltrans MCE response spectrum, whichever is greater, and two Lower Level Earthquakes (LLE) having 72-year and 150-year average return periods, respectively. A site-specific probabilistic seismic hazard analysis (PSHA) and a standard Caltrans deterministic analysis were performed to develop the target response spectrum at the soil model base. An equivalent-linear seismic response analysis using the computer program SHAKE91 (Idriss and Sun, 1992) was performed and compared with the nonlinear total-stress and effective-stress seismic response analyses using the computer code D-MOD2000 (GeoMotions, LLC, 2007). The ARS curve computed using the equivalent-linear approach significantly reduced the shorter period response, amplifying the longer period response. The equivalent-linear analysis cases used the preliquefaction and post-liquefaction soil properties. The surface ARS curves were further computed from the nonlinear analyses. Before the site-specific evaluation, a simplified ARS curve was recommended and used in the preliminary design. Differences and deficiencies of the surface ARS curves between using simplified method, the equivalent-linear and nonlinear effective-stress seismic response analyses are discussed and recommendations for bridge structures having different fundamental periods of vibration are provided.

• Corporate Authors:

  Multidisciplinary Center for Earthquake Engineering Research

  State University of New York, 107 Red Jacket Quadrangle, P.O. Box 610025
  Buffalo, NY  United States  14261-0025
• Authors:
  • Zhai, Endi
  • Makarechi, Houman
• Conference:
  • Sixth National Seismic Conference on Bridges and Highways
  • Location: Charleston SC, United States
  • Date: 2008-7-28 to 2008-7-30
• Publication Date: 2008

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Maps; References; Tables;
• Pagination: 10p
• Monograph Title: Sixth National Seismic Conference on Bridges and Highways: Seismic Technologies for Extreme Loads

Subject/Index Terms

• TRT Terms: Box girder bridges; Bridge design; Earthquake engineering; Earthquake resistant design; Liquefaction; Long span bridges; Seismicity; Soil remediation
• Uncontrolled Terms: Probabilistic seismic demand model (Bridge engineering); Seismic response; Soil properties
• Subject Areas: Bridges and other structures; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 01356904
• Record Type: Publication
• Files: TRIS
• Created Date: Nov 16 2011 2:51PM