Tests and improvement of bridge elastomeric bearings and software development for their preliminary design

The present paper focuses on both existing and new R/C bridge overpasses and aims at a) the design and pilot production of elastomeric (steel-laminated) bearings, specifically by a local Hellenic industry, which then can be used in practice, b) the investigation of the mechanical properties of these pilot bearings at the Laboratory of Strength of Materials of Aristotle University and c) the development of a an expert system which can link the produced elastomeric bearings as well as same type bearings that are usually employed with the current design practice in the selection of an appropriate elastomeric bearing scheme for typical R/C bridge overpasses in Greece. Along these lines a series of tests were performed on unit slice specimens of properties and dimensions representative of the pilot bearings. Summary results are presented in this paper of the aforementioned ongoing experimental investigation along with the measured mechanical characteristics under standard loading sequences. Numerical simulations are performed for validation processes for the development of the expert system based on the Greek Guidelines for the design of bridges with seismic isolation and Eurocode 8Part 2 Annex for the design of bridges. Summary information of this expert system is presented herein; it is aimed for selecting, during preliminary design, a set of ‘optimal’ bearings from a database of commercially available ones, inclusive the foreseen pilot production. This selection process is based on the criteria set by the Greek Guidelines for seismic isolation, engineering judgment as well as on international standards. It is believed that the above described scheme can contribute towards a better link between production that is based on local industries and needs, experimentally-based optimization and final seismic design of bridge structures.