Stability Analysis of Curved Bridge Swivel Construction
When a curved bridge constructed using the rotation method suddenly stops during rotation,the bridge will withstand inertial forces,self-weight,and wind loads,which may cause significant deform-ation and local structural instability,leading to engineering accidents.On the basis of stability research on swivel construction,the main consideration is the influence of rotational speed and wind speed on the out of plane stability coefficient of the bridge.Taking a railway crossing an existing railway as an example,the out of plane stability coefficient of the bridge is taken as the control objective during the swivel construc-tion process.Through stability theory analysis,equations between rotational speed and out of plane stabil-ity coefficient,as well as equations between wind speed and out of plane stability coefficient,have been es-tablished during the swivel process.The results show that when the rotational speed is low,the wind speed has a greater impact on the stability of the rotating system,while when the rotational speed is high,the wind speed has a smaller impact on the stability of the rotating system.When the wind speed is low,the emergency stop time has a greater impact on the stability of the rotating system,while when the wind speed is high,the emergency stop time has a smaller impact on the stability of the rotating system.To ensure the safety of the rotating construction process,the rotational acceleration should not exceed 0.1°/s2 when the wind speed is less than 8 m/s.When the wind speed is 8 m/s-18 m/s,the impact of the speed on the external stability coefficient k2 is relatively small,and the speed can be controlled within 0.01 rad/s while ensuring safety.