重载铁路桥梁抗剪加固措施

Shear Strengthening Measures for Heavy Haul Railway Bridge

由于朔黄重载铁路扩能改造,桥梁结构出现了明显的梁端劣化现象,影响其使用性能和安全性能。以一座朔黄重载铁路32 m跨度预应力混凝土简支梁桥为对象,研究采用粘贴钢板法和钢板-混凝土组合加固法对桥梁进行抗剪加固后桥梁抗剪承载力的提高情况,并提出加固后桥梁梁端抗剪箍筋应力的计算公式。结果表明:采用钢板-混凝土组合加固后,抗剪承载力整体上提升幅度大于粘贴钢板法;粘贴钢板法施工更方便快捷。两种加固方案均可降低箍筋应力,有效提高梁端承载力,不仅满足承载力要求,也增加了结构的安全储备。在满足施工要求的条件下可根据工程实际选用合理的加固方法。本文提出了两种方法加固后的箍筋应力计算公式,发现两种加固方法中箍筋的应力均显著减小。

Due to the capacity expansion and reconstruction of Shuozhou-Huanghuagang heavy haul railway,the bridge structure has obvious girder end deterioration,which affects its service performance and safety performance.Taking a 32 m span prestressed concrete simply supported girder bridge of Shuozhou-Huanghuagang heavy haul railway as the object,the improvement of the shear bearing capacity of the bridge after the shear reinforcement of the bridge by the bonding steel plate method and the steel plate concrete composite reinforcement method was studied,and the calculation formula of the shear stirrup stress at the girder end of the bridge after the reinforcement was proposed.The results show that the shear capacity of the steel plate concrete composite strengthening method is larger than that of the bonding steel plate method.The two reinforcement schemes proposed in this paper can reduce the stirrup stress and effectively improve the girder end bearing capacity,which not only meets the bearing capacity requirements,but also increases the safety reserve of the structure.Under the condition of meeting the construction requirements,the reasonable reinforcement method can be selected according to the actual situation of the project.In this paper,the calculation formulas of stirrup stress after two methods of reinforcement are proposed,and it is found that the stirrup stress in the two methods of reinforcement is significantly reduced.