既有铁路浅基桥墩的加固设计和施工技术

青海省东部湟水河一既有铁路浅基桥墩受常年流水冲刷影响基础和桥墩局部冲刷严重,导致河床对基础的约束强度降低,桥墩自振频率和横向振幅超限,横向刚度严重不足。据此,提出对既有基础底部进行注浆处理,增补桩基和外包钢筋混凝土加固既有桥墩的方法,介绍了主要加固设计内容及主要工序的施工技术。通过理论分析可知该加固设计对于提高桥墩横向刚度和自振频率有显著效果,可为既有铁路浅基桥墩及相关结构的加固提供参考。

Strengthening Design and Construction Technique for Shallow Foundation Piers of Existing Railway Bridge

Some shallow foundation piers of an existing railway bridge over Huangshui river in eastern Qinghai province are affected by perennial running water scouring,and the foundation and pier local scour are severely,resulting in the reduction of the restraint strength of the foundation,the excessive pier natural frequency and transverse amplitude,and the serious insuff iciency of transverse stiffness.Based on this phenomenon,the methods of grouting at the bottom of existing foundation,adding pile foundation and w rapping reinforced concrete to reinforce existing piers were put forw ard. The main reinforcement design contents and construction technique of main procedures were introduced. Through theoretical analysis,it can be know n that the reinforcement design has a significant effect on improving the pier transverse stiffness and frequency,and can provide a reference for the reinforcement of shallow foundation piers of existing railway bridge and related structures.