Study on the Seismic Performance of Different Combinations of Rubber Bearings for Continuous Beam Bridges

Abstract

Rubber isolation bearings have been proven to be effective in reducing the seismic damage of bridges. Due to the different characteristics of isolation bearings, the mechanical properties of bridges with different combinations of rubber bearings are complex under the action of earthquakes. This paper focuses on the application of combinations of rubber isolation bearings on seismic performance of continuous beam bridges with T-beams. The seismic performances of continuous beam bridges with different combinations of rubber isolation bearings, pier height, and span length were studied by the dynamic time history analysis method. It was found that the bridges with natural rubber bearings (NRBs) have the largest seismic responses compared to the other types of bearings. The continuous beam bridge with isolation bearings, such as lead rubber bearings (LRBs) and high damping rubber bearings (HDRBs), has approximately 20%∼30% smaller seismic response than that with NRBs under the action of earthquakes due to the hysteretic energy of the bearings, indicating that the isolation bearings improve the seismic performance of the bridge. The continuous beam bridges with both NRBs and LRBs or NRBs and HDRBs have larger seismic response of the piers than those with a single type of isolation bearings (LRBs or HDRBs) but smaller seismic response of the piers than those with only NRBs. For a continuous beam bridge with shorter span and lower pier, it is not economical to use LRBs or HDRBs underneath every single girder, but it is more reasonable to use cheaper NRBs underneath some girders. The larger difference in stiffness of the bearings between the side and middle piers leads to the more unbalanced seismic response of each pier of the bridge structure. The results also show that with increasing pier height and span length, the difference in the seismic response value between the cases gradually increases.

Evaluación experimental y numérica del uso de caucho reciclado como apoyo elastomérico en modelos de puentes simplemente apoyados

“…De manera similar a lo que pasa en el tablero, la mayor reducción se pudo observar cuando se incluyeron los apoyos en láminas de caucho reciclado, lo cual contribuye a un mejor funcionamiento de la estructura. De igual forma, en la evaluación del esfuerzo cortante que se puede apreciar en la figura 8, se pudo establecer que el uso de apoyos en los modelos reduce los esfuerzos al interior de los elementos estructurales; asimismo, para los elementos anteriormente mencionados, se encontró que el uso de apoyos en láminas de caucho reciclado resulta más óptimo si se compara con los apoyos de neopreno, lo cual concuerda con el comportamiento descrito por Zhang et al [27].…”

Seismic Vulnerability Analysis of Long-Span Prestressed Concrete Composite Box Girder Bridge with Corrugated Steel Webs under Construction

“…However, the above studies mainly focused on the seismic vulnerability of completed bridges. The research on continuous girder bridges under construction mainly stays at the level of structural seismic response analysis [7][8][9], and there are few reports on structural damage assessment during the construction stage. Hsu et al [10] proposed a construction classification and vulnerability analysis framework for existing buildings from the perspective of earthquake insurance.…”

Probabilistic Damage Analysis of Isolated Steel Tub Girder Bridge Excited by Near and Far Fault Ground Motions

“…Nonlinear dynamic history studies are performed to explore the sensitivity impacts of isolation duration, friction coefficient, limits on sliding deformation and the bridge reactions. The analysis shows that by employing proper friction coefficients, the drift and ductility may be reduced [4]. The ensemble of horizontal components of actual earthquake ground motions are studied in order to determine the seismic effect of multi-span continuous bridges decoupled by sliding isolators and elastomeric bearings.…”