Mechanical Characteristics Analysis And Construction Monitoring Of A Self-anchored Suspension Bridge

With the rapid development of the national economy and the continuous improvement of infrastructure,the requirements for the span and aesthetics of highways and river bridges are getting higher and higher.As a complex bridge structure system,self-anchored suspension bridges have many uncertain factors in the construction and operation process.These factors affect the construction and safe operation of the bridge.In this paper,the Shenyang East Tower Suspension Bridge is taken as the research object.The combination of theoretical analysis,finite element simulation and on-site monitoring is used to study the static and dynamic characteristics of the suspension bridge construction process.The main contents are as follows:(1)The related theoretical research of self-anchored suspension bridge is carried out,and the principle and applicable conditions of static calculation theory,partial vibration theory and moving load triangle analysis model of suspension bridge are analyzed.(2)The finite element model of Shenyang East Tower Suspension Bridge is established.From the bare tower stage to the operation stage,it is divided into five groups of load conditions.The static performance of the main structure of the suspension bridge under various working conditions is simulated by finite element software.The internal force values of the structures and components under various working conditions were obtained and compared.(3)The moving load time history of the suspension bridge is analyzed,and the measurement points of the deflection,acceleration and bending moment of the bridge deck are studied by taking 1/2 of the mid-span and 1/2 of the span.The research results show that the bending moment and deflection are less affected by the load speed,and the acceleration is greatly affected by the speed.The bending moment and deflection are linearly affected by the load velocity,and the acceleration changes nonlinearly.(4)In the finite element software,the influence of stiffness on the vibration characteristics of the suspension bridge is analyzed by changing the stiffness coefficient setting of the main structure of the suspension bridge.The results show that thevibration characteristics of the suspension bridge are more affected by the main tower and the steel box girder,which is not significantly affected by the cable system..(5)Combined with the structural characteristics of the project,the construction method and the requirements of the construction party,the monitoring plan for each construction stage of the whole bridge shall be formulated,and the specific points and monitoring frequency of the main bridge tower,steel box girder and boom stress monitoring shall be determined.In the construction process,the stress of the main bridge tower,steel box girder and boom is monitored in real time,and the monitoring results and their changing rules are summarized and analyzed,and the first-hand construction safety evaluation data is provided for the constructor..(6)Comparing the actual monitoring data at each construction stage with the numerical simulation results under the corresponding working conditions,the two are in good agreement,indicating that the model establishment and simulation analysis are correct.The above research on the mechanical properties of typical self-anchored suspension bridges under static and dynamic loads can provide reference for the design,construction and safe operation of similar self-anchored suspension bridges in the future.