| Since Chinese economic reform, country’s economy has made great development. The major infrastructure construction of roads and bridges also have been improving. Through the end of 2011, the number of highway bridges in our country reached nearly 700000.Among them, a considerable part of highway bridges has been used more than 40 years. As times goes on, more and more highway brigde has to face the problem of structural damage and materials aging. The bearing capacity and seismic performance of aging brigde has seriously degraded. Therefore,this paper mainly do research in several ways about the problem of aging bridges:1、The reasonable reinforce corrosion model was choosed in this paper. Based on the OpenSees finite element analysis platform, the three-dimensional finite model of the isolated continuous girder brigde is established at five different aging time node. And the modal analysis of this brigde model is taken.2、The uncertainty of structure materials and the reinforcement corrosion model by using the Latin hypercube sampling. Based on cloud method, seismic fragility analysis of the isolated contiuous girder bridge at five aging time node was done. The results indicate that seismic fragility of overall brigde and isolation bearing have a little increasement as time goes on, but seismic fragility of the pier increased significantly.3、The parameters changing in the seismic fragility formula can be quadratic fit about the function of time. Thus, the new seismic fragility formula was obtained, which can predict the seismic fragility at any time node.4、According to the equal exceeding probability principle, the earthquake value in the five time node was adjusted. On the other hand, the earthquake resistance value of the peir in the five time node was got based on the pushover analysis of the pier. According to camparing the earthquake value with the earthquake resistance value of the peir, the elastic seismic performance of the pier was evaluated. |
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