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基于氯离子腐蚀作用模型,对混凝土中钢筋锈蚀机理及过程开展了研究,进而建立了钢筋直径及屈服强度的退化模型。为了研究氯离子侵蚀对隔震桥梁抗震性能的影响,选取我国某一长期处于海洋潮汐环境中受氯离子腐蚀影响显著的近海隔震桥梁为算例,基于Open Sees平台分别建立了不考虑和考虑钢筋腐蚀的全桥有限元模型,然后选取15条合适的地震波进行了IDA分析,并根据构件需求能力比建立了板式橡胶支座和桥墩在不同破坏状态下的易损性曲线,最终基于概率论知识完成了全桥的系统易损性曲线。计算结果表明:对于隔震桥梁而言,板式橡胶支座比桥墩更容易发生破坏;全桥系统比任何单一构件都更容易发生破坏,采用全桥易损性曲线评价桥梁的抗震性能更加合理;考虑钢筋腐蚀后,全桥地震易损性增强,说明在氯离子侵蚀环境下,钢筋的腐蚀问题不可忽略。
Based on the model of chloride ion corrosion, the corrosion mechanism and process of rebar in concrete are studied, and then the degradation model of rebar diameter and yield strength is established. In order to study the influence of chloride ion erosion on the seismic performance of isolated bridges, a long-term offshore seismic isolation bridge which is significantly affected by chloride ion corrosion in the ocean tidal environment is selected as an example. Based on the Open Sees platform, Then, fifteen suitable seismic waves were selected for IDA analysis, and the vulnerability curves of plate rubber bearings and piers under different failure conditions were established according to the component demand capability ratio. Finally, based on the theory of probability Knowledge completes the full-bridge system vulnerability curve. The calculated results show that the plate rubber bearing is more prone to damage than the bridge piers for the isolated bridges. The full bridge system is more prone to damage than any single component. It is more reasonable to evaluate the seismic performance of the bridge by using the full bridge vulnerability curve. After considering the corrosion of steel bar, the vulnerability of full-bridge earthquakes is enhanced, which indicates that the corrosion of steel bars can not be neglected in the environment of chloride ion erosion.