Dynamic characteristics of a long span seismic isolated bridge

• Published in: Engineering structures Vol. 25; no. 12; pp. 1479 - 1490
• Main Authors: Boroschek, Rubén L., Moroni, María O., Sarrazin, Mauricio
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.10.2003; Elsevier
• Subjects: Ambient vibration; Applied sciences; Base isolated bridge; Bridges; Buildings. Public works; Earthquake response; Exact sciences and technology; Response records; Stresses. Safety; Structural analysis. Stresses; Structural monitoring; South America; Chile; America; Base isolated bridge; Structural monitoring; Earthquake response; Ambient vibration; Response records; Dynamic response; Dynamic characteristic; Construction parameter; Displacement(deformation); Seismic design code; Bridges; Bearing deflection test; Vibrational analysis; Rubber; Base insulation; Monitoring; Field study; Vibration insulation
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/S0141-0296(03)00113-5

The central zone of Chile is located in a high seismic risk area with occurrence of magnitude 7 earthquakes every 10 years and magnitude 8 events every 90 years. This paper deals with the mechanical and dynamic characteristics of a 383 m long seismic isolated bridge located in that area. The tests carried out on rubber components, isolators and the bridge structure are presented. Some simple structural models that show good correlation with measured response are also addressed. A strong motion permanent network installed on the bridge allowed the recording of ambient-traffic vibrations as well as seismic motions. Seismic records show the beneficial effect of the isolation in the horizontal direction, but important amplification occurs in the vertical direction for relatively high frequency components.