Seismic and Traffic Load Modeling on Cable Stayed Bridge
Long span cable stayed bridges are usually characterized by numerous, closely spaced low natural frequencies below 1 Hz. For a particular combination of cable and deck frequencies, large amplitude cable vibrations due to parametric excitation may occur even for considerably low traffic, wind or seismic loading. The mechanism of parametric excitation is well described theoretically for simple academic cases. However, due to the complexity of the parametric resonance phenomenon, analysis of bridges for this purpose is only possible by using explicit Finite Element (FE) simulations. This paper presents a FE analysis of the Bill Emerson Memorial Bridge subject to seismic and traffic loading and their influence on vibrations of the cables. The development of the FE model of the bridge for use with the LS-DYNA® code is described. The model was validated by comparison of calculated natural frequencies with experimentally determined values. The bridge was subjected to seismic loading registered during the Northridge earthquake. This simulation revealed large oscillations of the cables that were induced by the tower lateral vibrations. However, the vibrations did not lead to excessive stresses in cables. A simplified model representing the AASHTO HS 20-44 truck was also developed. The truck model was used to simulate traffic loading on the bridge. The interaction between the truck and the bridge deck was defined through a special LS-DYNA algorithm – RAIL. In this paper, cases with one and twenty trucks on the bridge were examined. No excessive cable vibrations due to traffic loading were observed.
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Corporate Authors:
500 Fifth Street, NW
Washington, DC United States 20001 -
Authors:
- Bojanowski, Cezary
- Kulak, Ronald F
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Conference:
- Transportation Research Board 90th Annual Meeting
- Location: Washington DC, United States
- Date: 2011-1-23 to 2011-1-27
- Date: 2011
Language
- English
Media Info
- Media Type: DVD
- Features: Figures; Maps; Photos; References; Tables;
- Pagination: 13p
- Monograph Title: TRB 90th Annual Meeting Compendium of Papers DVD
Subject/Index Terms
- TRT Terms: Cable stayed bridges; Finite element method; Long span bridges; Simulation; Structures; Traffic loads; Truck traffic; Vibration; Wind
- Identifier Terms: Bill Emerson Memorial Bridge; Northridge Earthquake, January 17, 1994
- Uncontrolled Terms: Seismic loading
- Subject Areas: Bridges and other structures; Highways; I24: Design of Bridges and Retaining Walls;
Filing Info
- Accession Number: 01340717
- Record Type: Publication
- Report/Paper Numbers: 11-2553
- Files: TRIS, TRB
- Created Date: May 23 2011 7:15AM