考虑氯离子腐蚀作用的近海桥梁结构全寿命抗震性能评价

发布时间：2018-11-21 09:40

【摘要】：基于全寿命理念的桥梁结构全寿命抗震性能设计与评价方法,是近年来国内外桥梁工程领域普遍关注的热点课题。主要研究了氯离子腐蚀作用在全寿命周期内对钢筋混凝土近海桥梁结构抗震性能的影响,结合氯离子对钢筋混凝土结构的腐蚀作用模型,提出了基于时变腐蚀电流密度的钢筋混凝土结构在氯离子腐蚀作用下钢筋腐蚀程度公式。取某一长期受海洋潮汐环境中氯离子腐蚀作用影响的近海桥梁工程结构为算例,考虑桥梁墩柱内纵筋直径、力学性能以及混凝土性能在全寿命周期内的退化效应,对各个寿命周期阶段内的算例桥梁进行Pushover分析和增量动力分析,并通过易损性分析方法对全寿命周期内桥梁的抗震性能进行了评价。研究结果表明,随着氯离子腐蚀作用的进行,桥梁结构在全寿命周期内的抗震能力不断降低,地震动作用下的抗震需求不断增加,到达极限破坏状态的概率不断增加。该桥梁结构全寿命抗震性能评价方法可为桥梁结构全寿命抗震性能设计提供参考。
[Abstract]:The design and evaluation method of seismic performance of bridge structures based on the concept of full life is a hot topic in the field of bridge engineering at home and abroad in recent years. In this paper, the effect of chloride corrosion on seismic behavior of reinforced concrete offshore bridge structures during the whole life cycle is studied, and the corrosion model of reinforced concrete structures is combined with chloride ions. A formula for corrosion degree of reinforced concrete structures under chloride ion corrosion is proposed based on time-varying corrosion current density. Taking an offshore bridge structure affected by chloride ion corrosion in ocean tidal environment for a long time as an example, the degradation effect of longitudinal reinforcement diameter, mechanical properties and concrete properties in the bridge pier column during the whole life cycle is considered. The Pushover analysis and incremental dynamic analysis are carried out for the bridge in each life cycle, and the seismic performance of the bridge in the whole life cycle is evaluated by the method of vulnerability analysis. The results show that with the corrosion of chloride ions, the seismic capacity of bridge structure decreases continuously in the whole life cycle, the seismic demand under the action of ground motion increases and the probability of reaching the ultimate failure state increases. The whole life seismic performance evaluation method can be used as a reference for the whole life seismic performance design of bridge structure.
【作者单位】：大连理工大学建设工程学部;
【基金】：国家重点基础研究发展计划(973计划)(2011CB013605) 国家自然科学基金重大研究计划重点项目(90815026) 国家自然科学基金委创新研究群体基金(51121005)
【分类号】：U445.73;U442.55

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