基于结构健康监测系统数据的桥梁竖向预应力筋断裂事件安全分析与整治预防研究

Safety Analysis and Remediation Prevention of Vertical Prestressed Reinforcement Fracture Events in Bridges Based on Structural Health Monitoring System Data

竖向预应力筋是防止预应力混凝土桥梁腹板主拉应力开裂的有效手段。为了研究部分竖向预应力缺失对桥梁结构整体及断裂部分的影响,基于某特大型连续刚构桥结构健康监测数据,探究了预应力筋断裂前后梁体竖向挠度及振动数据的变化。研究结果表明:结构跨中竖向挠度变化趋势均与环境温度变化趋势较为一致,振动幅值及大桥自振频率在竖向预应力钢筋断裂前后未发生明显变化,大桥整体处于安全状态;而竖向预应力筋部分断裂会加剧断裂处裂缝的产生。

Vertical prestressing tendons are an effective means to prevent cracking of prestressed concrete bridge web plates under tensile stress.In order to study the impact of partial vertical prestressing deficiency on the overall structure and fracture parts of the bridge,based on the health monitoring data of a large continuous rigid frame bridge structure,the changes in vertical deflection and vibration data of the beam before and after prestressing tendon fracture were analyzed.The research results indicate that the trend of vertical deflection variation in the mid span of the structure is consistent with the trend of environmental temperature variation.The vibration amplitude and natural frequency of the bridge did not show significant changes before and after the fracture of the vertical prestressed steel bars,and the bridge as a whole is in a safe state;The partial fracture of vertical prestressed reinforcement will exacerbate the occurrence of cracks at the fracture site.