QUICK RELEASE PULLBACK TESTING AND ANALYTICAL SEISMIC ANALYSIS OF A SIX SPAN COMPOSITE GIRDER BRIDGE

A six span four hundred and fifty foot long continuous composite girder bridge has been subjected to extensive dynamic testing to identify its structural dynamic properties. Transverse motions were induced by quick release pullback testing and vertical motions were induced by normal vehicular traffic. Analysis of the data obtained indicates that this type of dynamic testing is very effective for bridge structures of this type. After obtaining the experimental dynamic properties, a linear analytical model was used for purposes of comparison with the experimental results and for estimating the seismic forces induced by small to moderate earthquakes having recurrence times on the order of 30 to 40 years in Western Nevada. Results of this analysis indicate that the earthquake forces prescribed by the AASHTO specifications (1961), under which this bridge was designed, are too low for seismic regions of the Western United States. The 300-pound per linear foot minimum transverse wind load controlled in the design, but dynamic seismic analysis indicates that lateral forces in excess of four or five times those caused by the wind loads would be expected to occur every 30 to 40 years. The peak ground motions associated with the earthquakes used in this study are about 14 percent of the largest ground motions ever recorded during an earthquake.

  • Corporate Authors:

    University of Nevada, Reno

    Department of Civil Engineering
    Reno, NV  United States  89557

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Douglas, B M
  • Publication Date: 1976-8

Media Info

  • Pagination: 82 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00151724
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FHWA-RD-76-173 Final Rpt.
  • Contract Numbers: DOT-FH-11-8311
  • Files: NTIS, TRIS, USDOT
  • Created Date: Apr 27 1977 12:00AM