高强钢筋ECC-RC复合桥梁地震易损性分析

Seismic fragility analysis of ECC-RC composite bridge with high-strength steel bar

考虑高强钢筋、ECC等高性能材料在桥梁工程中的推广应用,针对普通钢筋混凝土桥墩抗震性能相对较差的情况,研究高强钢筋ECC-RC复合桥墩的桥梁抗震性能。通过OpenSees平台建立普通RC桥墩桥梁、ECC-RC复合桥墩桥梁及高强钢筋ECC-RC复合桥墩桥梁非线性有限元模型,采用增量动力法和“能力需求比”分析方法建立桥梁各构件及系统的地震易损性曲线,探讨高强钢筋及ECC对桥梁抗震性能的影响。研究表明:ECC-RC、高强钢筋ECC-RC复合桥墩及其桥梁系统的地震易损性均有改善,且高强钢筋ECC的改善效果更显著,高强钢筋ECC-RC复合桥墩支座的地震易损性有所降低,高强钢筋及ECC的应用有助于提高桥墩和桥梁系统抗震性能和安全性,特别是在中震及大震作用下这一现象更加明显。

Based on the popularization and application of high-performance materials such as high-strength steel bars and ECC in engineering,this paper studies the seismic performance of ECC-RC composite bridge piers with high-strength steel bars in view of the relatively poor seismic performance of ordinary reinforced concrete piers.The nonlinear finite element models of common RC pier bridge,ECC-RC composite pier bridge and high-strength steel bar ECC-RC composite pier bridge are established by OpenSees platform.The seismic fragility curves of bridge components and systems are established by incremental dynamic method and‘capacity demand ratio’analysis method to explore the influence of high-strength steel and ECC on the seismic performance of bridges.Research shows that the seismic fragility of ECC-RC,high-strength steel bar ECC-RC composite pier and its bridge system are improved,and the improvement effect of high-strength steel bar ECC is more significant.In addition,the seismic fragility of ECC-RC composite pier bearing with high-strength steel bar is reduced.The application of high-strength steel bar and ECC helps to improve the seismic performance and safety of bridge piers and bridge systems,especially under the action of moderate and large earthquakes.