A parametric study on the axial behaviour of elastomeric isolators in multi-span bridges subjected to horizontal seismic excitations
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- 作者：E. Tubaldi ; S. A. Mitoulis ; H. Ahmadi ; A. Muhr
- 关键词：Bridges ; Seismic isolation ; Steel ; laminated elastomeric bearings ; Tensile stress ; Buckling ; Shape factor
- 刊名：Bulletin of Earthquake Engineering
- 出版年：2016
- 出版时间：April 2016
- 年：2016
- 卷：14
- 期：4
- 页码：1285-1310
- 全文大小：1,553 KB
- 刊物类别：Earth and Environmental Science
- 刊物主题：Earth sciences
Geotechnical Engineering
Civil Engineering
Geophysics and Geodesy
Hydrogeology
Structural Geology - 出版者：Springer Netherlands
- ISSN：1573-1456
文摘
This paper investigates the potential tensile loads and buckling effects on rubber-steel laminated bearings on bridges. These isolation bearings are typically used to support the deck on the piers and the abutments and reduce the effects of seismic loads and thermal effects on bridges. When positive means of fixing of the bearings to the deck and substructures are provided using bolts, the isolators are exposed to the possibility of tensile loads that may not meet the code limits. The uplift potential is increased when the bearings are placed eccentrically with respect to the pier axis such as in multi-span simply supported bridge decks. This particular isolator configuration may also result in excessive compressive loads, leading to bearing buckling or in the attainment of other unfavourable limit states for the bearings. In this paper, an extended computer-aided study is conducted on typical isolated bridge systems with multi-span simply-supported deck spans, showing that elastomeric bearings might undergo tensile stresses or exhibit buckling effects under certain design situations. It is shown that these unfavourable conditions can be avoided with the rational design of the bearing properties and in particular of the shape factor, which is the geometrical parameter controlling the axial bearing stiffness and capacity for a given shear stiffness. Alternatively, the unfavourable conditions could be reduced by reducing the flexural stiffness of the continuity slab.