Bi-directional implementation of multiple-slider surface bearing to girder bridges: simplified 3-D modelling and seismic performance assessment

Abstract

The uplifting slide shoe (UPSS) bearing, consisting of multiple sliding surfaces, is a new type of bearing which has been proposed to achieve reduced displacement under strong earthquakes without losing advantage of the slide bearing to deal with the thermal effects on bridges girders. In the present study, bi-directional implementation of the UPSS devices is proposed to achieve effectiveness in controlling the bi-directional seismic response of girder bridges induced by bi-directional ground motions. A simplified multi-spring model of the bi-directional UPSS, considering the coupling effect of the friction mechanism and the geometric contact condition of the slider, is established to assess the bi-directional bridge response including the integrated nonlinear interaction between the longitudinal and transverse components. Numerical simulations demonstrate that the bi-directional UPSS is effective in reducing the pier response in the transverse direction compared with the conventional UPSS. The seismic performance of the bridge with the application of the bi-directional UPSS is shown to be superior to that of the functionally discrete bearing (FDB) systems in effectively reducing both the bearing displacement and the pier response ductility factor.

Keywords:

• Multi-span continuous girder bridge
• bi-directional earthquake excitation
• multiple planes sliding surface bearing
• 3-D numerical model
• seismic performance assessment

Acknowledgements

The study presented in this paper is conducted under the collaboration with the UPSS device development research group, and the result and investigation are accomplished based on the collective knowledge and discussion with the members of the research group. Contribution of Dr. Hiroshige Uno (formerly Oiles Corp.), Dr. Yukio Adachi (Hanshin Expressway Engineering Co. Ltd.), Dr. Tomoaki Sato (Hanshin Expressway Co. Ltd.), Prof. Taiji Mazda (Kyushu Univ.), and members of JIP Techno Science Corp. is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.