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Roebling Suspension Bridge. II: Ambient Testing and Live-Load Response |
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| Authors: | Wei-Xin Ren Issam E Harik George E Blandford M Lenett T M Baseheart |
| Affiliation: | 1Professor, Dept. of Civil Engineering, Fuzhou Univ., Fuzhou, Fujian Province, People’s Republic of China; and Professor, Dept. of Civil Engineering, Central South Univ., Changsha, Hunan Province, People’s Republic of China. 2Professor, Dept. of Civil Engineering, Univ. of Kentucky, Lexington, KY 40506-0281 (corresponding author). 3Professor, Dept. of Civil Engineering, Univ. of Kentucky, Lexington, KY 40506-0281. 4Structural Engineer, URS Corp., Cincinnati, OH 45221. 5Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Cincinnati, Cincinnati, OH 45221-0071. |
| Abstract: | This is the second part of a two-part paper on the evaluation of the historic Roebling suspension bridge using dynamic-analysis techniques. Dynamic properties are determined using ambient field testing under natural excitation. The finite-element (FE) model described in the first part of this two-part paper is modified to more accurately represent current bridge properties. Modifications of the model are based on correlating the FE model frequencies with ambient test frequencies by adjusting the FE model stiffness parameters. The updated 3D FE model is subsequently subjected to an extreme live-load condition to evaluate static safety margins. In addition, cable areas are reduced by 10 to 40% to simulate further deterioration and corrosion. The safety margin of the main cables is demonstrated to be good even when assuming a very conservative 40% cable area reduction, and truss member forces remain within the maximum load-carrying capacity even when the cable areas are reduced by 40%. |
| Keywords: | Bridges suspension Finite element method Vibration Natural frequency Bridge tests Bearing capacity Evaluation Ohio Kentucky |