Study On Seismic Performance And Hybrid Test Of Continuous Girder Bridge Retrofitted By FRP Jackets

Reinforced concrete pier is the key component to the seismic performance of bridge. The failure of the piers during an earthquake will lead to disastrous consequences. At present, the ductility seismic design method for bridge has been widely adopted by the seismic code around the world. For bridges in service, in order to control the failure mode of the piers and improve the seismic performance of the bridge structure, FRP retrofitting is an effective way. For experimental study of structures’ seismic performance, hybrid test is an advanced seismic test method, which overcomes shortcomings of FEA and traditional seismic experiment methods. From the perspective of structure, this paper attempts to implement the seismic performance analysis of a continuous girder bridge with the method of hybrid test technology, which performs more efficient and accurate, and to find a reasonable FRP retrofitting method to improve the seismic performance of the bridge piers. The main works of this paper are as follows:(1) Summarized the research status of bridge seismic, FRP retrofitting of bridge piers and hybrid test of bridge, and presented some direction worthy for further research. Summarized some analysis and calculation methods of bridge seismic performance which are commonly used.(2) Took a continuous girder bridge with double column piers as the research object, analyzed its mechanical behavior, failure mode, and FRP retrofitting method. Established the finite element model of the bridge with OpenSees. Analyzed the seismic performance of the pier with Push-over analysis and low frequency cycle loading analysis, analyzed the seismic performance of the whole bridge model with dynamic time history analysis.(3) According to the similar scale of 1/2.5, two bridge pier model were made, one of the piers was retrofitted with FRP at the plastic hinge region. The hybrid test of the bridge with two different kinds of piers were conducted. The results of the experiment showed the well seismic performance of the FRP retrofitted piers and validated the reliability of the hybrid test model.In this paper, the research focused on the seismic performance of the whole bridge and took EFA and hybrid test as the main research means. In this paper, a reasonable FRP seismic retrofitting method was put forward. It was the first time that the hybrid test technology was used to study the seismic performance of continuous girder bridge retrofitted by FRP jackets, and realized the application of the hybrid test in the study of a bridge seismic performance.