胜利黄河大桥病害高强螺栓节点修复及桥面板补强技术

Rehabilitation of Damaged High-Strength Bolted Joints and Bridge Deck Strengthening Techniques for Shengli Huanghe River Bridge

胜利黄河大桥主桥为(60.5+136.5+288+136.5+60.5)m连续钢箱梁斜拉桥,桥面板采用正交异性钢桥面板,钢箱梁节段横缝采用摩擦型高强螺栓(Friction-type High-Strength Bolt,FHSB)连接。受人为和自然环境因素影响,该桥运营33年后出现了横缝FHSB节点锈蚀、接触面磨光、正交异性钢桥面板U肋焊缝开裂与脱落、横缝折角等病害。对该桥病害进行统计及成因分析,并提出病害FHSB节点修复及超高性能混凝土(Ultra-High Performance Concrete,UHPC)桥面板补强技术。拆除横缝位置处的原连接U肋拼接板,按照“纵横对称间隔拆除”的原则拆除原桥螺栓群,喷砂处理节点接触面,螺母侧朝下重新栓接更换的拼接板,栓焊新增的U肋拼接板,最后铺装UHPC桥面板。通过理论分析及数值模拟,对比分析了加固前、后横缝FHSB节点的抗滑承载力及主梁结构性能,并进行全桥荷载试验。结果表明:加固后,横缝FHSB节点抗滑承载力恢复至设计值,修复施工阶段桥梁结构安全可靠,改造后主梁结构性能满足规范要求。

The main bridge of Shengli Huanghe River Bridge is a cable-stayed bridge with a main span of 288 m,two side spans of 136.5 m and two end spans of 60.5 m.The superstructure consists of steel box girders and orthotropic steel deck panels,in which the steel box girder segments were connected by friction-type high-strength bolts(FHSBs).After 33 years of operation,the bridge exhibited various deteriorations due to both human and environmental factors,including the rusted FHSB joints and wear-down of contacting surfaces,as well as cracking of the welded joints between orthotropic steel deck plates and U-ribs,falling of bolts and bending of bolted joints.The deteriorations were statistically collected and the causes were analyzed.It was suggested to rehabilitate the FHSB joints by adding bolts and strengthening the deck via adding a UHPC course.The original splice plates of U-ribs at the bolted joints were dismantled,the original bolt groups were removed,following the principle of removing the bolts in the longitudinal and transverse rows symmetrically and at intervals.The contacting surfaces of bolted joints were sandblasted,and new splice plates were added via the new bolts that had their nuts facing down.Afterwards,the new splice plates of U-ribs were bolted,and the UHPC course was cast.Theoretical analysis and numerical simulation were conducted,and the results demonstrate that the anti-slip capacity of the FHSB joints and structural performance of the superstructure after the rehabilitation were restored to the design values.The bridge structure was safe during the rehabilitation and met the code requirements after the rehabilitation.