Study On Mechanical Characteristic Of Lead-rubber Bearing And The Response Of Isolated Bridge With The Lead-rubber Bearing

The structural seismic performance of bridges can be improved significantly by applying seismic isolation technology. In this dissertation, the potential of using lead-rubber bearing to achieve seismic isolation have been studied in three stages.First, a series of mechanical characteristic tests for lead-rubber bearing was taken. The relations among the mechanical properties of lead-rubber bearing with its different structure dimension and load have been studied. The result indicates that the mechanical properties of lead-rubber bearing mainly depend on its geometry structure and material components. And the properties are reasonably stable during loading and unloading reciprocating cycle. By statistically analyzing the test data, a regression formula has been attained.Second, the influences of seismic wave, foundation of a bridge and the mechanical properties of lead-rubber bearing on the response of an isolated bridge with the lead-rubber bearing was investigated. Several conclusions for properly applying lead-rubber bearing in isolated bridges have been made.Last, two examples, of the response of a bridge with the lead-rubber bearing, were designed and analyzed based on the conclusions and the regression formula from this dissertation. The first example is a city-railway Continuous-beam bridge. The earthquake load of its main pile was reduced by over 80 percent. The second sample is a railway Simple-beam bridge. The earthquake load of its main pile was reduced by over 50 percent. Both are obviously excellent improvements.