A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Response of the Dumbarton Bridge in the Loma Prieta Earthquake
The Dumbarton bridge was the only major San Francisco Bay area bridge instrumented with strong motion accelerometers at the time of the October 17, 1989, Loma Prieta earthquake. The strong motion acceleration records are valuable data for improving the engineering of the earthquake response of long, multiple-span bridges on soft clay soils. Evaluation of the recorded motion of the bridge in the earthquake shows that the deck experienced a significant amplification of the ground motion recorded at the free field. The bridge has a large number of vibration modes closely spaced at frequencies less than 2 Hz (periods greater 0.5 sec). The fundamental vibration frequency of the instrumented spans is 0.52 Hz (vibration period of 1.9 sec) which is associated with longitudinal vibration of the main channel structure. The transverse mode of the approach structure has significant energy at 0.62 Hz (1.6 sec). A detailed three-dimensional model of the Dumbarton bridge was developed to represent the forty-three spans, the piers, and the pile foundations. The computed motion for four cases of the model and input motion is compared with the recorded motion of the bridge in the Loma Prieta earthquake. The case with non-uniform ground motion, cable restrainers between the approach and main channel structures, and longitudinal release of the hangers in the main channel structure provides the best correlation with recorded earthquake motion.
Response of the Dumbarton Bridge in the Loma Prieta Earthquake
The Dumbarton bridge was the only major San Francisco Bay area bridge instrumented with strong motion accelerometers at the time of the October 17, 1989, Loma Prieta earthquake. The strong motion acceleration records are valuable data for improving the engineering of the earthquake response of long, multiple-span bridges on soft clay soils. Evaluation of the recorded motion of the bridge in the earthquake shows that the deck experienced a significant amplification of the ground motion recorded at the free field. The bridge has a large number of vibration modes closely spaced at frequencies less than 2 Hz (periods greater 0.5 sec). The fundamental vibration frequency of the instrumented spans is 0.52 Hz (vibration period of 1.9 sec) which is associated with longitudinal vibration of the main channel structure. The transverse mode of the approach structure has significant energy at 0.62 Hz (1.6 sec). A detailed three-dimensional model of the Dumbarton bridge was developed to represent the forty-three spans, the piers, and the pile foundations. The computed motion for four cases of the model and input motion is compared with the recorded motion of the bridge in the Loma Prieta earthquake. The case with non-uniform ground motion, cable restrainers between the approach and main channel structures, and longitudinal release of the hangers in the main channel structure provides the best correlation with recorded earthquake motion.
Response of the Dumbarton Bridge in the Loma Prieta Earthquake
G. L. Fenves (author) / F. C. Fifippou (author) / D. T. Sze (author)
1992
186 pages
Report
No indication
English
Highway Engineering , Soil & Rock Mechanics , Seismic effects , Girder bridges , Dynamic response , Structural vibration , Pile foundations , Bending moments , Displacement , Frequencies , Earthquake engineering , Earth movements , Accelerometers , California , Damping , Earthquake damage , Earthquakes , Soil-structure interactions , Loma Prieta Earthquake , Dumbarton Bridge , San Francisco(California)
Response of Struve-Slough Bridge Under the Loma Prieta Earthquake
| British Library Conference Proceedings | 1990
Simulation of the 1989 Loma Prieta Earthquake
| British Library Conference Proceedings | 1994
1989 Loma Prieta earthquake summary report
TIBKAT | 1989
Lessons Learned From the Loma Prieta Earthquake
| Wiley | 1991
Liquefaction at Moss Landing during Loma Prieta Earthquake
| Online Contents | 1997