Study On Mechanical Properties Of High Damping Rubber Isolation Pot Bearing

Earthquake is a kind of natural disaster that can’t be accurately predicted and avoided, which often brings great loss to the society when happening. In earthquake, the damage and collapse of structures brings massive loss. The bridge as the key to the traffic network plays a very important role in earthquake rescue work. The continuous beam bridge is one of the common bridge. In China, horizontal supporting system of the continuous beam bridge is mostly setting fixed bearings on only one pier within a league of continuous beam bridge. Therefore, in earthquake, the longitudinal seismic force of the bridge of the pier which is erected fixed bearings is much greater than the others, so it can’t give full play to the joint role of the pier group. In order to solve this problem, many scholars have conducted extensive research.This paper is devoted to the study of the mechanical properties of a new type of high damping rubber isolation pot bearing. This type of bearing is composed of the conventional unidirectional sliding pot bearing and the series system of the I-steel with high damping rubber which is added to restrict the over-displacement. After this kind of bearing being erected at the top of the fixed pier of continuous beam bridge, the series system of the I-steel with high damping rubber will play a role when the relative displacement between piers and beam exceeds limit, transfering the energy of the beam to the piers and limiting the relative displacement between the piers and beam.Firstly, the elastic-plastic mechanical properties of the I-steel is analyzed in this paper, and the calculation formula of the F—△ and the main mechanical parameter is obtained. Secondly, the conclusion that the high damping rubber pad is a kind of appropriate structural form is obtained by discussing the mechanical properties of different structural forms of high damping rubber. Thirdly, the mechanical properties of the new type of bearing under static loading mode and dynamic loading mode are analyzed, and the dynamic hysteretic model is obtained by dynamic hysteresis analysis. In this paper, the new type of bearing is applied to a five span continuous beam bridge for seismic analysis. The analysis shows that the new type bearing not only has a good effect on homogenizing the longitudinal bending moment at the bottom of the pier group, but also has a great effect on limiting the relative displacement between piers and beam. In addition, the performance of the new type bearing under different PGA and different local site condition is compared and analyzed, and it is found that the performance of the new type bearing under different conditions is different. Generally speaking, in earthquake, the bigger the relative displacement between piers and beam, the better the performance of the new type of bearing.