近场地震作用下锈蚀钢筋混凝土桥墩的IDA分析

利用锈蚀钢筋混凝土柱的滞回试验结果,验证钢筋混凝土构件中锈蚀模型的正确性;利用钢筋混凝土框架的振动台试验结果,验证用OPENSEES程序进行钢筋混凝土结构非线性动力分析的可行性.在此基础上,从PEER地震数据库中选取了30条地震记录,采用OPENSEES建立弹塑性有限元动力分析模型,对钢筋锈蚀的钢筋混凝土桥墩在远场地震、近场非脉冲地震和近场脉冲地震作用下的性能进行非线性时程分析,研究桥墩柱在三类地震作用下的反应,以及钢筋锈蚀对结构地震响应的影响.针对近场脉冲地震对结构进行增量动力分析(Incremental dynamic analysis,IDA),得到结构的IDA曲线和近场地震作用下钢筋锈蚀对结构抗震性能的影响.分析结果表明,在考虑钢筋锈蚀因素时,近场脉冲地震对结构抗震性能影响最为显著,在结构抗震设计中应引起注意.

Incremental Dynamic Analysis of Corroded Reinforced Concrete Bridge Columns Subjected to Near-field Earthquake

Using the hysteresis test results of corroded reinforced concrete columns, the accuracy of the model of corroded steel in reinforced concrete structures was validated. The feasibility of OPENSEES program for the nonlinear dynamic analysis of reinforced concrete structure was verified with the shaking-table test results of reinforced concrete frame. With the program and 30 seismic ground motions selected from the PEER database, a dynamic elastic-plastic finite element model was built. And then, the seismic performance of a corroded reinforced concrete bridge column subjected to far-field earthquake, near-field earthquake with or without impulse action was measured by the nonlinear dynamic time-history analysis in order to study the steel corrosion effect on the structural response under three types of earthquake ground motions. Aiming at the near-field earthquake with impulse action, the Incremental Dynamic Analysis (IDA) was carried out, the IDA curves and the influence of steel corrosion on the seismic performance of the bridge columns were obtained. The results show that near-field earthquake with pulse action has the most significant effect on the structural seismic performance when considering the corrosion, and special attention should be paid to that during structural seismic design.