Characterization of the Cyclic Behavior of Corroded Steel Bridge Bearings and their Influence on Seismic Bridge Performance.

Steel Bridge Bearings;Corrosion Effect;Seismic Performance;Civil and Environmental Engineering;Engineering;Civil Engineering

Fan, XiaohuEl-Tawil, Sherif ;

University of Michigan

关键词: Steel Bridge Bearings;    Corrosion Effect;    Seismic Performance;    Civil and Environmental Engineering;    Engineering;    Civil Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/109030/xhfan_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Steel bridge bearings are widely used in existing bridges in the United States to provide a load transfer mechanism and accommodate movements between the superstructure and substructure. Due to a lack of regular maintenance, the in-situ condition of these steel bearings is often severely corroded. Moreover, these steel bearings are not designed for seismic loads due to a lack of understanding of the seismic hazard posed to bridges in the Central and Eastern United States (CEUS) at the time that many of these bridges were built. As awareness of their susceptibility to corrosion and vulnerability to seismic loads increases among bridge owners and engineers, the seismic performance of steel bearings and their influence on the overall bridge system performance is of major concern, particularly given the importance the highway network plays in sustaining economic prosperity. For this reason, the goal of this study is to correlate corrosion level with the performance of steel bearings under seismic loads, thereby providing a means of more accurately assessing the vulnerability of in-situ bridges.An analytical and finite element study is first undertaken to gain a preliminary understanding of the mechanical behavior of the considered steel bearings. Corrosion loss quantification and large-scale experimental testing are then conducted on 25 salvaged steel bridge bearings aiming to provide an in-depth understanding of corrosion loss distribution and its influence on the cyclic behavior of steel bearings. Further, a portfolio of constitutive models that incorporate corrosion effects is created for the steel bridge bearings based on the experimental findings. The seismic performance of the steel bearings and the bridge systems is then numerically evaluated considering design basis earthquakes and maximum credible earthquakes.Overall, the findings of this study show that significant corrosion can develop on steel bearings over their service life, which can result in major changes to the cyclic behavior of steel bearings. The numerical simulations suggest that steel rocker bearings, when used in a continuous steel girder bridge, have the potential to topple in the longitudinal direction regardless of corrosion level. The bolster bearings also can lead to large forces transferred to the bridge wall piers.