轨道专用连续刚构桥钢-混结合段疲劳性能

Fatigue performance of steel-concrete joint section of continuous rigid frame bridge for specific track use

为了验证特大跨轨道连续刚构桥钢-混结合段的疲劳性能,根据应力等效原则设计了结合段局部1∶2缩尺模型,开展了疲劳验证和疲劳破坏试验,测试了疲劳荷载加载过程中结合段关键构件的应力变化情况和钢-混界面的滑移变化情况。结果表明:在200万次疲劳验证加载过程中,结合段应力水平较低,各测点应力变化不大,界面相对滑移很小,钢结构无表观裂纹,具有良好的抗疲劳性能;在100万次疲劳破坏加载过程中,各测点应力均略微增大,相对滑移量也有所增大,但钢结构仍无表观裂纹,结构具有足够的疲劳安全储备。

In order to verify the fatigue performance of the steel-concrete joint section of the long-span track continuous rigid frame bridge,a local 1∶2 scale model of the joint section was designed according to the principle of stress equivalence.Fatigue verification and fatigue failure tests were carried out.The stress changes of the key components of the joint section and the slip changes of the steel-concrete interface were tested during the fatigue loading process.The test results show that in the process of 2 million fatigue verification loadings,the stress level of the joint section is low,and the stress changes at each measuring point is not large,and the relative slippage of the interface is small,and the steel structure has no apparent cracks,and it has good fatigue resistance.During the loading process of 1 million fatigue failures,the stress of each measuring point increases slightly,and the relative slip amount also increases,but the steel structure still has no apparent cracks,and the structure has sufficient fatigue safety reserves.