大跨多塔斜拉桥火灾后PC主梁损伤程度评估方法研究

Research on Evaluation Method of PC Main Beam Damage Degree after Fire of Long-span and Multi-tower Cable-stayed Bridge

某四塔双索面预应力混凝土斜拉桥在合拢前,6#索塔左幅锚固区内发生火灾,事故导致结构出现严重损伤,经紧急抢险和索力恢复后,结构损伤得到一定缓解,为科学指导结构合拢以及后续加固设计提供依据,需对主梁的损伤程度进行准确评估。提出了以实测数据为依据,联合实体及杆系有限元模型对PC主梁的损伤程度进行评估的方法。与实测结果对比表明,本文提出的评估方法准确有效,可为同类结构的损伤识别提供重要参考。

a fire broke out in the left anchorage zone of 6# tower of a four-tower double cable plane prestressed concrete cable-stayed bridge. The accident caused serious damage to the structure, and the structural damage was relieved after emergency rescue and cable recovery. To provide a basis for scientific guidance structure closure and reinforcement design, it is necessary to accurately assess the damage degree of the main beam. This paper proposes a method to evaluate the damage degree of PC main beam based on measured data and combined solid and link finite element model. The results shows that the evaluation method proposed in this paper is accurate and effective, and can provide an important reference for damage identification of similar structures.