Title: The European Approach to the Seismic Isolation of Bridges

Author(s): Renzo Medeot

Publication: Symposium Paper

Volume: 164

Issue:

Appears on pages(s): 131-142

Keywords: bridge bearings; damping; earthquake-resistant structures; bridges (structures); energy dissipation; Structural Research

DOI: 10.14359/1440

Date: 11/1/1996

Abstract:
The first application of Base Isolation within the European Union dates back to 1974, when this design approach was adopted for the Somplago Viaduct in Italy. The numerous solutions adopted since that time are based upon different functioning principles and the use of various materials. There are substantial differences between the classes of devices used in new projects or in cases of retrofit projects. Nonetheless, all have an essential characteristic in common: the elements which transmit vertical loads (bearing devices) are clearly distinct from those that control horizontal loads resulting from either seismic or service actions (re- centering/dissipating devices). In this manner, certain important advantages, which the paper illustrates in detail, can be gained. In addition, as it concerns the case of retrofit projects, the solutions adopted in order to insure the structure's seismic protection are so implemented as to not alter the original restraint scheme, i. e., the fixed and expansion points are not changed. Thus, the structure responds to service loads in the manner conceived by its original designer. This paper illustrates these concepts through the illustration of some particular cases.