DBPapers
DOI: 10.5593/SGEM2015/B13/S5.105

DYNAMIC RESPONSE OF A SPECIAL BRIDGE IN ROMANIA USING DIFFERENT TYPES OF SEISMIC ISOLATORS

I. R. Racanel
Friday 7 August 2015 by Libadmin2015

References: 15th International Multidisciplinary Scientific GeoConference SGEM 2015, www.sgem.org, SGEM2015 Conference Proceedings, ISBN 978-619-7105-33-9 / ISSN 1314-2704, June 18-24, 2015, Book1 Vol. 3, 807-814 pp

ABSTRACT
Earthquakes are external actions which can occur several times during the service life of a bridge structure and can produce damages, leading even to the structural collapse with severe consequences in social and economic life. The effects of last major seismic events produced worldwide in Chile, Turkey, Japan and other countries led to the enhancement of the design methods, provisions and standards, in order to achieve a safety level that can be accepted in service.
Romanian territory includes several seismic faults covering a major part of the country, the seismic action being considered in the design stage for a new bridge structure. In the past, the desired safety factor for a bridge, considering the seismic action, was reached by increasing the dimensions and through this the stiffness of the structural elements. In present time, the desired level of safety can be obtained by introducing special devices and controlling the bridge response under seismic action, with real benefits regarding the costs of the structure.
In this paper, the behavior under seismic action of a new bridge equipped with passive control devices is investigated. The bridge is placed at Păuleşti in Romania and was designed in a special solution, a concrete roundabout, which allow the crossing of the national road DN1B by a county road DJ102 using the smallest ground area. Two types of passive control devices are used: high-damping and lead-rubber bearings. Finally a comparison between the dynamic response of the non- and isolated structure is presented. Moreover, the influence of increasing the isolator effective damping on the bridge response is shown and discussed.

Keywords: bridge, earthquake, stiffness, rubber bearings, effective damping